Rebuild GitLab with latest stable CE version

[JedMeister]

Marcos noted on the forums that the version of GitLab we're currently shipping is EOL and the upgrade process from the current version we ship and the latest is not ideal.

So releasing an updated app ASAP would make life easier for all new TurnKey GitLab users.

There are also a couple of outstanding TKL FitLab issues that would be nice to close as well:

• Confconsole / GitLab appliance issue with Let's Encrypt certificate setup. #1515 (pretty old one!)
• GitLab - missing dependency (seems to be non-critical and easily fixed by end user) #1819

Also, it may not longer be relevant, but there is also an LXC login issue open: #1819. We should double check it and either fix the issue or close it.