Fixed placement of close button on merge requests

app/views/projects/merge_requests/_discussion.html.haml

 - content_for :note_actions do
   - if can?(current_user, :update_merge_request, @merge_request)
     - if @merge_request.open?
-      = link_to 'Close merge request', merge_request_path(@merge_request, merge_request: {state_event: :close }), method: :put, class: "btn btn-nr btn-comment btn-grouped btn-close close-mr-link js-note-target-close", title: "Close merge request", data: {original_text: "Close merge request", alternative_text: "Comment & close merge request"}
+      = link_to 'Close merge request', merge_request_path(@merge_request, merge_request: {state_event: :close }), method: :put, class: "btn btn-nr btn-comment btn-close close-mr-link js-note-target-close", title: "Close merge request", data: {original_text: "Close merge request", alternative_text: "Comment & close merge request"}
     - if @merge_request.closed?
-      = link_to 'Reopen merge request', merge_request_path(@merge_request, merge_request: {state_event: :reopen }), method: :put, class: "btn btn-nr btn-comment btn-grouped btn-reopen reopen-mr-link js-note-target-reopen", title: "Reopen merge request", data: {original_text: "Reopen merge request", alternative_text: "Comment & reopen merge request"}
+      = link_to 'Reopen merge request', merge_request_path(@merge_request, merge_request: {state_event: :reopen }), method: :put, class: "btn btn-nr btn-comment btn-reopen reopen-mr-link js-note-target-reopen", title: "Reopen merge request", data: {original_text: "Reopen merge request", alternative_text: "Comment & reopen merge request"}
 
 #notes= render "projects/notes/notes_with_form"