Merge branch '10444-ee-diff-commits-show' into 'master'

Move EE differences for `app/views/projects/commits/show.html.haml`

Closes #10444

See merge request gitlab-org/gitlab-ee!12960

app/views/projects/commits/show.html.haml

@@ -30,7 +30,7 @@
             = link_to project_commits_path(@project, @ref, rss_url_options), title: _("Commits feed"), class: 'btn' do
               = icon("rss")
 
-    = render 'projects/commits/mirror_status'
+    = render_if_exists 'projects/commits/mirror_status'
 
     %div{ id: dom_id(@project) }
       %ol#commits-list.list-unstyled.content_list