The GitLab status plugin should be able to be manually disabled

[hacker1024]

Is your feature request related to a problem? Please describe.

At the moment, the GitLab status plugin is enabled as long as gitlab_authorization is set.

This is not always desired, though. For example, when testing changes to Hydra before deployment, it can be useful to use gitlab_authorization for the GitLab PR plugin without publishing status reports.

Describe the solution you'd like

There should be a dedicated configuration option to allow disabling the GitLab status plugin.