Loosened checks on Pubsubhubbub response Content-Type to include text/xml and application/xml

git-svn-id: http://framework.zend.com/svn/framework/standard/trunk@21234 44c647ce-9c0f-0410-b52a-842ac1e357ba

library/Zend/Feed/Pubsubhubbub/Subscriber/Callback.php

@@ -106,6 +106,8 @@ class Zend_Feed_Pubsubhubbub_Subscriber_Callback
             && $this->_hasValidVerifyToken(null, false)
             && ($this->_getHeader('Content-Type') == 'application/atom+xml'
                 || $this->_getHeader('Content-Type') == 'application/rss+xml'
+                || $this->_getHeader('Content-Type') == 'application/xml'
+                || $this->_getHeader('Content-Type') == 'text/xml'
                 || $this->_getHeader('Content-Type') == 'application/rdf+xml')
         ) {
             $this->setFeedUpdate($this->_getRawBody());