Reverts b1b4ba501f, 90c9801c56, a3c84f78ca, ..
I haven't really traced it (yet), but on some servers, I'm observing
`ansible-playbook ... --tags=start` completing very slowly, waiting
to stop services. I can't reproduce this on all Matrix servers I manage.
I suspect that either the systemd version is to blame or that some
specific service is not responding well to some `docker kill/rm` command.
`ExecStop` seems to work great in all cases and it's what we've been
using for a very long time, so I'm reverting to that.
Also get rid of `--tags=update-user-password` in the
`matrix-dendrite` role, as what we had doesn't work.
We may be able to do it with some Ansible helper or something else.
For now, we'll omit this feature.
All the `matrix_s3_*` stuff happens in the `matrix-synapse` role.
If we are to have such S3 support for Dendrite, we should probably
extract it out of the `matrix-synapse` role (into a `matrix-s3` role or
`matrix-goofys`, etc.) and wire `matrix-dendrite` accordingly.
This may or may not be done in the future though. For now, I'm
cleaning things up in the `matrix-dendrite` role.
