Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2180

Just specifying `15` means we won't automatically re-pull `15.1` when it comes out.

We're overriding these in the correct way in `group_vars/matrix_servers`
so this wasn't causing any problem in practice.

.. when `matrix_nginx_proxy_enabled: false`

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/2177

These Postgres configuration variables are part of the `database.yaml` file
and don't need to be here.

This allows people to augment the Synapse image with custom tools and
addons without having to rebuild it from scratch.

If customizations are enabled, the playbook will build a new
`localhost/matrixdotorg/synapse:VERSION-customized` image
on top of the default one (`FROM matrixdotorg/synapse:VERSION`)
and with custom Dockerfile build steps.

For servers that self-build the Synapse image, the Synapse image will be
built first, before proceding to extend it the same way.

In the future, we'll also have easy to enable Dockerfile build steps
for modules that the playbook supports.

In the future, we'll also inject media storage providers that we support
into the `matrix_synapse_media_storage_providers_auto` list.

* fix room account data retrieving

* show recipient's email (header `TO`)
* add `norecipient` option
* add anti-spam options (`spamcheck:` and `spamlist:`)
* fix bugs

We don't like updating to untagged releases, but..

0.2.1 has some regression and upstream is not releasing 0.2.2 or 0.3.0
just yet, so we either need to downgrade to 0.2.0 or go `latest`.

We can hopefully switch back to a tagged release soon.

Related to https://github.com/mautrix/instagram/issues/56

all other bridges use that level

as per documentation: "Services that need no further configuration are enabled by default" and feeds service doesn't require it

Fixes a regression introduced in d1b5681ba0.

Looks like `.finished` is a property on the main object, not on some
`.async_result` object.

This also disables self-building on arm64, since it's no longer
necessary: https://github.com/matrix-org/matrix-appservice-slack/pull/656

We were previously trying to reach into `.rc`,
but there's no such thing if `async_result.finished == 0`.

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/2153

- Don't put unnecessary Host header.
- Update both cases (with or without nginx proxy)