Fixes a regression caused by a5ee39266c.

If the user id and group id were different than 991:991
(which used to be a hardcoded default for us long ago),
there was a mismatch between what Synapse was trying to use (991:991)
and what it was actually started with (in `--user=..`). It was then
trying to change ownership, which was failing.

This was mostly affecting newer installations which were not using the
991:991 defaults we had long ago (since a1c5a197a9).

This allows us to benefit from helpful things it does for us,
like enabling jemalloc: https://github.com/matrix-org/synapse/pull/8553

We weren't going through `start.py` before, because it was causing some
conflict with our `docker run --user=...` stuff, but it doesn't seem
to be a problem anymore.

Having done this, we won't need to do things like
https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/941
anymore.

fix typo

Set X-Forwarded-Proto on federation requests

ot -> to

matrix.{{ matrix_domain }} -> {{ matrix_server_fqn_matrix }}

Also check if matrix_ssl_lets_encrypt_support_email is blank

Upgrade Etherpad (1.8.7 -> 1.8.12)

Another field with 'invalid input syntax for type smallint'

GoMatrixHosting v0.3.1 hotfix!

- removed build_database_list.yml

- add matrix_postgres_backup_databases to be build on top of matrix_postgres_additional_databases
- POSTGRES_DB is now directly set from matrix_postgres_backup_databases while building the templates/env-postgres-backup.j2

- adjusted env-postgres-backup.j2 to use the new role specific variables

matrix-awx - the GoMatrixHosting v0.3.0 initial PR

Added support for the Go-NEB bot

This may be especially helpful to existing playbook users
who happen to find themselves installing Go-NEB later on.

Updated Element 1.7.22 -> 1.7.23

matrix-nginx-proxy: specify Origin header, comply with CORS

Self-checks against the .well-known URIs look for the HTTP header
"Access-Control-Allow-Origin" indicating that the remode endpoint
supports CORS. But the remote server is not required to include
said header in the response if the HTTP request does not include
the "Origin" header. This is in accordance with the specification
[1] stating: 'A CORS request is an HTTP request that includes an
"Origin" header.'

This is in fact true for Gitlab pages hosting and that's why the
issue was identified.

Let's specify "Origin" header in the respective uri tasks performing
the HTTP request and ensure a CORS request.

[1] https://fetch.spec.whatwg.org/#http-requests

Adding vars to synapse for private servers