GitLab 8.6: labels are duplicated in issue filter combobox
User Story
As a user on the dashboard issue list page, when I open the label combobox I see duplicates of each label and I would like to see only one copy.
Elaboration
We have global labels setup for new projects and individual labels setup for older projects. If #2651 (closed) were tackled, I do not think we'd have gotten into this situation.