Support for the praefect option

[rudexi]

Pull Request (PR) description

Support for the praefect option in gitlab omnibus configuration.

Reference:
https://docs.gitlab.com/ee/administration/gitaly/praefect.html#praefect

This Pull Request (PR) fixes the following issues

Fixes partially #366

[rudexi]

It looks like the acceptance testing for CentOS 6 is failing.
This is not related to the change, but rather the repos for CentOS 6 need a fix.
Dropping CentOS 6 support could be a workaround.

References:
voxpupuli/puppet-redis#381
voxpupuli/voxpupuli.github.io#232

[smortex]

@rudexi Support for EOL OS was removed and the CI now works with GitLab 14.

Do you mind rebasing your changes on top of the master branch?

From your working directory:

git fetch origin         # Download the latest code we have here
git rebase origin/master # Move your commits on top of the main branch
git push -f              # Send the changes (-f is required because we re-wrote history)

[smortex]

Also note that you can skip updating REFERENCE.md: it often cause conflicts when we are dealing with multiple PRs that compete to update it; and we regenerate it when we roll a new release.

[baurmatt]

Hey @rudexi, are you still interested in getting this merged?