This is beacause nginx will do canonization of URIs before
proxy-passing if you add anything after the port host:port.

For example, with:

     location /anything {
          proxy_pass http://127.0.0.1:8008/anything;
     }

NGINX will perform canonization, but with:

     location /anything {
          proxy_pass http://127.0.0.1:8008
	  # With NO Trailing slash
     }

NGINX will pass the unaltered original request, included /anything, to
the upstream server.

Canonization leads to problem when federating to other matrix-synapse
instances. The observed bug was:

- User A on our server (@A:our.server) invites User B on external
server (@B:matrix.org).

- User B correctly receive the invite.

- User B try to join the room but the request timeout.

- On our.sever logs we see "signature tampered" errors related to
  incoming connection from the external server (matrix.org).

This commit fix the issue.

- User last official deb package from matrix.org

- Revised LDAP integration:
  * ldap_server, ldap_domain [ ldap_basedn ] config vraiables.
  * Bind a protected service account with a service password and
    start-tls

- Hardcoded matrix.lilik.it --> {{ ansible_hostname }}.{{ domain }}

- Sqlite -> Postgres

New variables:

- matrix_domain | default($domain)

this role variables will be used during templating
for nginx reverse proxy