Azure: fix subnet reserved ranges

[zmb3]

The reserved range is a range of IP addresses, so the output should reserve the first 10 IPs in each subnet, not only the 10th IP.
(This is already the case for the AWS and GCP templates in this repo.)

With this change, the output shows:

➜ terraform output stable_config_pas | jq .pas_subnet_range
"10.0.0.1-10.0.0.10"

[zmb3]

Note: my editor automatically formatted the changed files to match HCL convention of lining up the =. Let me know if you'd rather I back out the formatting changes for a cleaner diff, or keep the formatting changes here so the formatting is consistent.

[jaristiz]

Looks good to me, will schedule to merge it.

[sneal]

Thanks @zmb3 you're the best!