ZF-10526: is_a() fix

git-svn-id: http://framework.zend.com/svn/framework/standard/trunk@23096 44c647ce-9c0f-0410-b52a-842ac1e357ba

library/Zend/Wildfire/Channel/HttpHeaders.php

@@ -270,8 +270,7 @@ class Zend_Wildfire_Channel_HttpHeaders extends Zend_Controller_Plugin_Abstract
             return true;
         }
 
-        // use is_a() instead of 'instanceof' to avoid having to load the class
-        if (!is_a($this->getRequest(), 'Zend_Controller_Request_Http')) {
+        if (!($this->getRequest() instanceof Zend_Controller_Request_Http)) {
             return false;
         }