Fix bg for labels page when no labels present

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/views/projects/labels/index.html.haml

@@ -14,8 +14,8 @@
       = render @labels
     = paginate @labels, theme: 'gitlab'
   - else
-    .light-well
+    .nothing-here-block
       - if can? current_user, :admin_label, @project
-        .nothing-here-block Create first label or #{link_to 'generate', generate_namespace_project_labels_path(@project.namespace, @project), method: :post} default set of labels
+        Create first label or #{link_to 'generate', generate_namespace_project_labels_path(@project.namespace, @project), method: :post} default set of labels
       - else
-        .nothing-here-block No labels created
+        No labels created