Fix for"nginx and two other services boot loops" #966

Fix step 3 of Mjolnir instructions

fix nginx boot loop

This was causing a port conflict when `matrix_nginx_proxy_enabled: false`.

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/983

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/868

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/868

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/868

.. and prevent variable name overlap with `matrix-postgres` for the
other variables as well.

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/868

- Added a postgres-backup role

Allow special characters in Grafana password and upgrade Grafana

GoMatrixHosting v0.4.0 update

Couple of additional tweaks to the mjolnir docs

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/962

Add mjolnir

Add some advice about making Synapse faster

Upgrade synapse-simple-antispam (0.0.1 -> 0.0.3)

Upgrade Element (1.7.24 -> 1.7.24.1)

Also removes some duplicate table of contents entries in maintenance-synapse.md

matrix-nginx-proxy: add custom nginx options to nginx.conf.j2

Updates to mautrix-signal config

See these last commits:

tulir/mautrix-signal@4fc34330c1f6947aece67863b0d04da34c776f80

tulir/mautrix-signal@64bc5c36a509ba435a0b01cf44afb1b5d2642efd

tulir/mautrix-signal@ddda1666d41d28750cc59d070e4388b24add6ad9

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/963

This also simplifies Prerequisites, which is great.

It'd be nice if we were doing these checks in some optional manner
and reporting them as helpful messages (using
`matrix_playbook_runtime_results`), but that's more complicated.
I'd rather drop these checks completely.