Group permissions inheritance wrong displayed/calculated
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### Summary
While beeing the *owner* of a group I will be added as *owner* of newly created repositories in this group, which is what I would expect. But if a repository is moved from, for example private space to this group I am the *owner* of, I will be listed in the moved repository as *maintainer*.
### Steps to reproduce
* Create a group
* create some projects inside this group
* create a project in your own namespace
* move this project from own namespace to the group
* go to the details of the group and/or the members of the moved project
### Example Project
I created https://gitlab.com/schwedenmut-testgroup to show this behaviour.
*Testproject* and *testproject2* were created directly from the group details page whereas *testproject3* was moved from my personal space.
### What is the current *bug* behavior?
Either the moved project should obey the inherited and more important group roles and display this, because it seems that this *could* only be a display error because adding myself to the project with *Owner* role results in the following error:

### What is the expected *correct* behavior?
Display the correct role.
### Relevant logs and/or screenshots
| group display | group member display | project member display |
| ------ | ------ | ------ |
|  |  |  |
### Output of checks
This bug happens on GitLab.com
This bug happens on my GitLab CE gitlab-ce@1c1d47c59744ec3dbd0f2a71df14eed856a3f649
### Possible fixes
Have not yet looked into the related files, sry.
issue