Fix Telegram bridge HTTP proxying when not using matrix-nginx-proxy

From what I see, this was never implemented to begin with.

Fixes #189 (Github Issue).

roles/matrix-bridge-mautrix-telegram/tasks/setup_install.yml

@@ -112,7 +112,7 @@
         	proxy_pass http://$backend;
         {% else %}
         	{# Generic configuration for use outside of our container setup #}
-        	proxy_pass http://127.0.0.1:8080;
+        	proxy_pass http://127.0.0.1:9006;
         {% endif %}
         }