[Fix #393] Failed to set aws.thing_name (#506)

* Fix failed to set aws.thing_name

Author: victoraldir

fw/examples/c_mqtt/mos.yml

@@ -19,6 +19,7 @@ config_schema:
   - ["device.password", "test"]
   - ["i2c.enable", true]
 libs:
+  - origin: https://github.com/mongoose-os-libs/aws
   - origin: https://github.com/mongoose-os-libs/ca-bundle
   - origin: https://github.com/mongoose-os-libs/http-server
   - origin: https://github.com/mongoose-os-libs/ota-http-server