[BUG] "mentioned in commit" is not added for tags not belonging to branches
Created by: simonzack
If a commit is created which belongs to a tag but not a branch, then no "mentioned in commit" note will be added to the issue tracker, despite the tag being pushed to the repository.
Tags which don't belong to branches can happen when archiving commits by referencing them with a tag and deleting a branch.
Affects gitlab 7.4.2.