It is not possible to make a user Owner of a group without readding the user

Summary

If you are an Owner of a group and wish to promote an existing member of that group to Owner then you have to remove that user and readd as Owner.

Steps to reproduce

  1. Create a group
  2. Add user as anything but Owner
  3. Try to change the permissions to Owner

What is the current bug behavior?

Owner is not present in the list Screen_Shot_2017-04-19_at_13.08.04

What is the expected correct behavior?

Should see Owner included in the list.

Results of GitLab environment info

GitLab Enterprise Edition 8.17.4-ee ba6d2a14