applied 'null in rss2.js' fix from Quix0r, see

http://forum.yacy-websuche.de/viewtopic.php?p=19612#p19612

git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@6752 6c8d7289-2bf4-0310-a012-ef5d649a1542

htroot/js/rss2.js

@@ -152,7 +152,7 @@ function getRSS(url){
 function processRSS() {
   if (xhr.readyState == 4) {
     if (xhr.status == 200) {
-      if (xhr.responseText != null) {
+      if ((xhr.responseText != null) && (xhr.responseXML != null)) {
         RSS = new RSS2Channel(xhr.responseXML);
         showRSS(RSS);
       } else {