AMBARI-13527. Flume agent combobox doesn't work. (akovalenko)

ambari-web/app/styles/application.less

@@ -5777,7 +5777,9 @@ input[type="radio"].align-checkbox, input[type="checkbox"].align-checkbox {
     position: static;
   }
   .flume-agents-actions {
-    position: static;
+    .btn-group {
+      position: static;
+    }
     a {
       text-decoration: none;
     }