Milestones > id instead of iid

Created by: rtripault

Currently on 0a44ecf3a0eb7be66b2dbbb6e8404e3242a4b016

Summary When browsing a milestone issues, ids are displayed instead of iids

Steps to reproduce In a project with a milestone and some issues set to the milestone, browse to gitlab.tld/namespace/project/milestones/milestone_id and see the displayed IDs