[ZF-6852]returnResponse() null == $flag should be null === $flag

git-svn-id: http://framework.zend.com/svn/framework/standard/trunk@16347 44c647ce-9c0f-0410-b52a-842ac1e357ba

library/Zend/Rest/Server.php

@@ -157,7 +157,7 @@ class Zend_Rest_Server implements Zend_Server_Interface
      */
     public function returnResponse($flag = null)
     {
-        if (null == $flag) {
+        if (null === $flag) {
             return $this->_returnResponse;
         }