use docker url for maubot to contact synapse server

This is more secure as most setups do not expose admin API endpoints to the outside world.

.gitignore

@@ -10,3 +10,4 @@ flake.lock
 # ignore roles pulled by ansible-galaxy
 /roles/galaxy/*
 !/roles/galaxy/.gitkeep
+.idea/

roles/custom/matrix-bot-maubot/templates/config/config.yaml.j2

@@ -60,7 +60,7 @@ server:
 homeservers:
   {{  matrix_domain }}:
     # Client-server API URL
-        url: "https://{{ matrix_server_fqn_matrix }}"
+        url: "http://matrix-synapse:8008"
     # registration_shared_secret from synapse config
     # You can leave this empty if you don't have access to the homeserver.
     # When this is empty, `mbc auth --register` won't work, but `mbc auth` (login) will.