Undo ill-advised change

In #628 I proposed a CORS change that turns out not to be the root of the issue. Caffeine-addled diagnosis leads to sloppy thinking, and this change should be reverted. In fact, if left it will cause problems for new installations.

Update CORS for ma1sd

Even with the v2 updates listed in #503 and partially addressed in #614, this is still needed to enable identity services to function with Element Desktop/Web. Testing on multiple clients with a clean config has confirmed this, at least for my installation.

Update README.md -> 'many times' -> 'more than once'

Stating "many times" makes me think there is a finite amount of times I can run it before it *will* start causing trouble. But this is not true. So just state it can me ran more than once without causing trouble :)

Python requires docker package and other small improvements

Related to #620 (Github Pull Request).

Allow self-build images for Synapse-Admin

Hopefully fixes a regression caused by b106a9592e.

Related to #597 (Github Pull Request).

Add a secondary option on how to get access token

Enable ma1sd hashing by default

Replace gpg dependency for gnupg for debian compatibility

Potentially the CURLing could be a better approach, since then you don't leave spare sessions hanging.

Make ansible check mode runs silent, for non idempotent tasks

Bump version of mautrix-telegram to 0.8.2

fixes matrix users unable to delete messages

Added config sample for synapse admin with traefik 2

Update configuring-playbook-ma1sd.md

Add an example to open all domains for registration in relation to black- and whitelists.

Fix regression since 2a50b8b6bb (#597).

Dimension is intended to be embedded in various clients,
be it the Element service that we host (at element.DOMAIN),
some other Element (element-desktop running locally), etc.

Changelog here https://github.com/jitsi/jitsi-meet/releases/tag/stable%2Fjitsi-meet_4857

Nginx proxy headers

Fix capability names for synapse-admin