Correct local MQTT broker max connections param

[kstribrnAmzn]

Description of changes:
Snake case aMQTT broker max conections parameter
to match v0.11.3.

Ref - https://amqtt.readthedocs.io/en/v0.11.3/references/broker_config/

Issue #, if available:
Working on fixing the FreeRTOS/FreeRTOS demo failures.

Ref - FreeRTOS/FreeRTOS#1395

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[kstribrnAmzn]

I've tested this locally on my machine by running the following commands

python3 ./ssl-credential-creator/ssl_credential_creator.py
python3 ./localhost-mqtt-broker/localhost_mqtt_broker.py --root-ca-cert-path=root_ca_cert.crt --server-priv-key-path=server_priv_key.key --server-cert-path=server_cert.crt --host="127.0.0.1"

I get the following output:

[2026-03-04 15:49:58,255] :: DEBUG :: asyncio :: Using selector: KqueueSelector
[2026-03-04 15:49:58,256] :: INFO :: amqtt.broker.plugins :: Loading plugins from config
[2026-03-04 15:49:58,257] :: DEBUG :: amqtt.broker.plugins :: Loading plugin amqtt.plugins.logging_amqtt.EventLoggerPlugin
[2026-03-04 15:49:58,257] :: DEBUG :: amqtt.broker.plugins :: Loading plugin amqtt.plugins.logging_amqtt.PacketLoggerPlugin
[2026-03-04 15:49:58,267] :: DEBUG :: passlib.utils.compat :: loaded lazy attr 'SafeConfigParser': <class 'configparser.ConfigParser'>
[2026-03-04 15:49:58,267] :: DEBUG :: passlib.utils.compat :: loaded lazy attr 'NativeStringIO': <class '_io.StringIO'>
[2026-03-04 15:49:58,267] :: DEBUG :: passlib.utils.compat :: loaded lazy attr 'BytesIO': <class '_io.BytesIO'>
[2026-03-04 15:49:58,268] :: DEBUG :: amqtt.broker.plugins :: Loading plugin amqtt.plugins.authentication.AnonymousAuthPlugin
[2026-03-04 15:49:58,268] :: WARNING :: amqtt.broker.plugins.FileAuthPlugin :: Password file '/Users/kstribrn/workspace/forks/CI-CD-Github-Actions/localhost-mqtt-broker/passwd' not found
[2026-03-04 15:49:58,268] :: DEBUG :: amqtt.broker.plugins :: Loading plugin amqtt.plugins.authentication.FileAuthPlugin
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: Loading plugin amqtt.plugins.sys.broker.BrokerSysPlugin
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_pre_start' handler found for 'EventLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_post_start' handler found for 'EventLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_pre_shutdown' handler found for 'EventLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_post_shutdown' handler found for 'EventLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_client_connected' handler found for 'EventLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_client_disconnected' handler found for 'EventLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_client_subscribed' handler found for 'EventLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_client_unsubscribed' handler found for 'EventLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_retained_message' handler found for 'EventLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_message_received' handler found for 'EventLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_message_broadcast' handler found for 'EventLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'mqtt_packet_sent' handler found for 'EventLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'mqtt_packet_received' handler found for 'EventLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'mqtt_packet_sent' handler found for 'PacketLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'mqtt_packet_received' handler found for 'PacketLoggerPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_pre_start' handler found for 'BrokerSysPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_post_start' handler found for 'BrokerSysPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_pre_shutdown' handler found for 'BrokerSysPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_client_connected' handler found for 'BrokerSysPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'broker_client_disconnected' handler found for 'BrokerSysPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'mqtt_packet_sent' handler found for 'BrokerSysPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: 'mqtt_packet_received' handler found for 'BrokerSysPlugin'
[2026-03-04 15:49:58,275] :: DEBUG :: transitions.core :: Executed machine preparation callbacks before conditions.
[2026-03-04 15:49:58,275] :: DEBUG :: transitions.core :: Initiating transition from state new to state starting...
[2026-03-04 15:49:58,275] :: DEBUG :: transitions.core :: Executed callbacks before conditions.
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker :: State transition: new
[2026-03-04 15:49:58,275] :: INFO :: transitions.core :: Executed callback '<bound method Broker._log_state_change of <amqtt.broker.Broker object at 0x1055a4470>>'
[2026-03-04 15:49:58,275] :: DEBUG :: transitions.core :: Executed callback before transition.
[2026-03-04 15:49:58,275] :: DEBUG :: transitions.core :: Exiting state new. Processing callbacks...
[2026-03-04 15:49:58,275] :: INFO :: transitions.core :: Finished processing state new exit callbacks.
[2026-03-04 15:49:58,275] :: DEBUG :: transitions.core :: Entering state starting. Processing callbacks...
[2026-03-04 15:49:58,275] :: INFO :: transitions.core :: Finished processing state starting enter callbacks.
[2026-03-04 15:49:58,275] :: DEBUG :: transitions.core :: Executed callback after transition.
[2026-03-04 15:49:58,275] :: DEBUG :: transitions.core :: Executed machine finalize callbacks
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker :: Broker starting
[2026-03-04 15:49:58,275] :: DEBUG :: amqtt.broker.plugins :: Plugins len(_fired_events)=2
[2026-03-04 15:49:58,276] :: DEBUG :: amqtt.broker.plugins.EventLoggerPlugin :: ### 'on_broker_pre_start' EVENT FIRED ###
[2026-03-04 15:49:58,276] :: INFO :: amqtt.broker :: Listener 'default' bind to 127.0.0.1:1883 (max_connections=1000)
[2026-03-04 15:49:58,279] :: INFO :: amqtt.broker :: Listener 'tls' bind to 127.0.0.1:8883 (max_connections=1000)
[2026-03-04 15:49:58,279] :: DEBUG :: transitions.core :: Executed machine preparation callbacks before conditions.
[2026-03-04 15:49:58,279] :: DEBUG :: transitions.core :: Initiating transition from state starting to state started...
[2026-03-04 15:49:58,279] :: DEBUG :: transitions.core :: Executed callbacks before conditions.
[2026-03-04 15:49:58,279] :: DEBUG :: transitions.core :: Executed callback before transition.
[2026-03-04 15:49:58,279] :: DEBUG :: transitions.core :: Exiting state starting. Processing callbacks...
[2026-03-04 15:49:58,279] :: INFO :: transitions.core :: Finished processing state starting exit callbacks.
[2026-03-04 15:49:58,279] :: DEBUG :: transitions.core :: Entering state started. Processing callbacks...
[2026-03-04 15:49:58,279] :: INFO :: transitions.core :: Finished processing state started enter callbacks.
[2026-03-04 15:49:58,279] :: DEBUG :: transitions.core :: Executed callback after transition.
[2026-03-04 15:49:58,279] :: DEBUG :: transitions.core :: Executed machine finalize callbacks
[2026-03-04 15:49:58,279] :: DEBUG :: amqtt.broker.plugins :: Plugins len(_fired_events)=2
[2026-03-04 15:49:58,279] :: DEBUG :: amqtt.broker :: Broker started
[2026-03-04 15:49:58,279] :: DEBUG :: amqtt.broker.plugins.EventLoggerPlugin :: ### 'on_broker_post_start' EVENT FIRED ###
[2026-03-04 15:49:58,279] :: DEBUG :: amqtt.broker :: Retaining message on topic $SYS/broker/version
[2026-03-04 15:49:58,280] :: DEBUG :: amqtt.broker.plugins :: Plugins len(_fired_events)=3
[2026-03-04 15:49:58,280] :: DEBUG :: amqtt.broker.plugins.BrokerSysPlugin :: Setup $SYS broadcasting every 10 seconds
[2026-03-04 15:49:58,280] :: INFO :: amqtt.broker :: Starting session expiration monitor.
[2026-03-04 15:49:58,280] :: DEBUG :: amqtt.broker.plugins.EventLoggerPlugin :: ### 'on_broker_retained_message' EVENT FIRED ###