Merge branch 'revert-2d3563ab' into 'master'

Revert "Merge branch 'jivl-add-top-margin-related-merge-requests' into 'master'"

See merge request gitlab-org/gitlab-ce!19442

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

 - if @merge_requests.any?
-  .prepend-top-default
   %h2.merge-requests-title
     = pluralize(@merge_requests.count, 'Related Merge Request')
   %ul.unstyled-list.related-merge-requests