Add (Postgres + SQLite) support to matrix-mautrix-hangouts bridge

I don't use this bridge, so this is completely untested.

roles/matrix-bridge-mautrix-hangouts/templates/config.yaml.j2

@@ -27,7 +27,7 @@ appservice:
     # Format examples:
     #   SQLite:   sqlite:///filename.db
     #   Postgres: postgres://username:password@hostname/dbname
-    database: postgres://mautrix_bridge_hangouts:{{ matrix_additional_databases | selectattr('name', 'equalto', 'mautrix_bridge_hangouts') | map(attribute='pass') | first }}@{{ matrix_postgres_connection_hostname }}/mautrix_bridge_hangouts
+    database: {{ matrix_mautrix_hangouts_appservice_database|to_json }}
 
     # The unique ID of this appservice.
     id: hangouts

roles/matrix-bridge-mautrix-hangouts/templates/systemd/matrix-mautrix-hangouts.service.j2

@@ -18,6 +18,7 @@ ExecStartPre={{ matrix_host_command_docker }} run --rm --name matrix-mautrix-han
 			--log-driver=none \
 			--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
 			--cap-drop=ALL \
+			--network={{ matrix_docker_network }} \
 			-v {{ matrix_mautrix_hangouts_config_path }}:/config:z \
 			-v {{ matrix_mautrix_hangouts_data_path }}:/data:z \
 			{{ matrix_mautrix_hangouts_docker_image }} \