change mb-4 to 2

src/server/views/widget/not_creatable_content.html

@@ -1,4 +1,4 @@
-<div class="row not-found-message-row mb-4">
+<div class="row not-found-message-row m-2">
   <div class="col-md-12">
     <h2 class="text-muted">
       <i class="icon-ban" aria-hidden="true"></i>