Tags on detached HEAD not shown in Repository/Network
### Summary
When I create a tag on a detached HEAD (which is e.g. the default state in gitlab-ci), I am not able to see the tag in Repository/Network.
This is useful for Maven or Debian where the version number from `pom.xml` resp. `debian/control` is used as package version.
Just take the SHA1 of a successful commit, change the version number from the detached head, build (and upload) the release and then push the tag. We just defined a `manual` job in a stage after the successful build/test of a commit in master, which will do this.
By means of this, development may procure on master and we do not have the hassle with special release branches.
### Steps to reproduce
* Clone a project.
* Checkout the HEAD of master using the SHA1 (detached head)
* Change a file (e.g. the version number)
* Commit on the detached head
* Tag the detached head
* Push tags
* Checkout master again.
See https://gitlab.com/mfriedenhagen/network-and-tag-on-detached-head
### Expected behavior
When choosing the tag from the dropdown In Repository/Network I would like to see a one-commit-branch with the tag name.
### Actual behavior
I only see the master commits in Repository/Network
### Relevant logs and/or screenshots
See https://gitlab.com/mfriedenhagen/network-and-tag-on-detached-head/network/v2
### Possible fixes
(If you can, link to the line of code that might be responsible for the problem)
issue