Merge branch 'fix-activity-only-notice' into 'master'

Remove icon in activity only message on smaller screen widths

See merge request gitlab-org/gitlab-ce!26032

app/assets/javascripts/notes/components/discussion_filter_note.vue

@@ -34,7 +34,7 @@ export default {
 
 <template>
   <li class="timeline-entry note note-wrapper discussion-filter-note js-discussion-filter-note">
-    <div class="timeline-icon">
+    <div class="timeline-icon d-none d-lg-flex">
       <icon name="comment" />
     </div>
     <div class="timeline-content">