Revert "Merge branch '9748-fix-boards-milestones-controller-spec' into 'master'"
When https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25173 was merged to EE, the EE specs exposed some N+1 queries in Milestoneish#percent_complete
. Since we are reverting this via ttps://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25229, we need to revert the schema changes here, too.