Fix tls_hostname deprecation warning

[aaronraimist]

https://matrix.to/#/!PukFFdIcHgtaaHZflT:devture.com/$1621301900156624BMssm:matrix.org?via=matrix.org&via=maunium.net&via=tchncs.de

[spantaleev]

This is the error in question.

TASK [matrix-base : Ensure Matrix network is created in Docker] **********************************************************************************************************************************
[DEPRECATION WARNING]: The default value "localhost" for tls_hostname is deprecated and will be removed in community.docker 2.0.0. From then on, docker_host will be used to compute
tls_hostname. If you want to keep using "localhost", please set that value explicitly. This feature will be removed from community.docker in version 2.0.0. Deprecation warnings can be disabled
by setting deprecation_warnings=False in ansible.cfg.

Not sure if we should do anything about this.

We're not passing tls_hostname explicitly. Looks like this module will start defaulting to docker_host, which appears to default to unix://var/run/docker.sock. Such a new default value will probably also work for us.

[aaronraimist]

Perhaps we could either set it explicitly to unix://var/run/docker.sock or localhost at least temporarily until that version is released

[spantaleev]

docker_host: unix://var/run/docker.sock doesn't help.

tls_hostname: unix://var/run/docker.sock does.

Still, it's somewhat silly having to specify tls_hostname while tls has a default value of false. We don't use TLS, supposedly. This seems to be an Ansible (collection) bug, which appears to have already been fixed here: ansible-collections/community.docker#143

I guess we need to wait a while and the deprecation message will disappear.