Merge branch 'fix-merge-request-assignee-list' into 'master'
Use the user list from the target project in a merge request ### What does this MR do? This MR derives the assignable users from the target project. ### Why was this MR needed? In a merge request, the assignable users uses the list from the forked project, not the target project where the merge request will be going. For example, if I fork a project from the gitlab-org namespace into my personal namespace, make some changes, and then create a merge request, the only users I see are me. I think it makes more sense to show all the users in gitlab-org. This is a regression caused by 3954b78382e2. ### What are the relevant issue numbers? Closes #1535 See merge request !682