Merge branch '6352-move-ee-differences-for-show-html-haml' into 'master'

CE backport: "Move EE differences for app/views/projects/issues/show.html.haml"

See merge request gitlab-org/gitlab-ce!27440

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

@@ -77,6 +77,8 @@
 
       = edited_time_ago_with_tooltip(@issue, placement: 'bottom', html_class: 'issue-edited-ago js-issue-edited-ago')
 
+    = render_if_exists 'projects/issues/related_issues'
+
     #js-related-merge-requests{ data: { endpoint: expose_url(api_v4_projects_issues_related_merge_requests_path(id: @project.id, issue_iid: @issue.iid)), project_namespace: @project.namespace.path, project_path: @project.path } }
 
     - if can?(current_user, :download_code, @project)