Closes: #385

Currently, Nextcloud installation is a pain where a lot of jobs and pod
fail until NC is finally installed. Still they show up in proemetheus and
create noise, why we ignore them in this check.
Once we achieve a better NC installation we should revert this.

Closes: #379

Closes #217

Closes #135

We now add the letsencrypt staging CA bundle to the trust store
and validate certs against it.

Closes #132