MDL-21009 Group selector must use absolute links in order to work with javascript off (last minute stupid testing fix)

lib/grouplib.php

@@ -433,7 +433,7 @@ function groups_print_activity_menu($cm, $urlroot, $return=false, $hideallpartic
 
     // Display error if urlroot is not absolute (this causes the non-JS version
     // to break)
-    if (strpos($urlroot, 'htxtp') !== 0) { // Will also work for https
+    if (strpos($urlroot, 'http') !== 0) { // Will also work for https
         debugging('groups_print_activity_menu requires absolute URL for ' .
             '$urlroot, not <tt>' . s($urlroot) . '</tt>. Example: ' .
             'groups_print_activity_menu($cm, $CFG->wwwroot . \'/mod/mymodule/view.php?id=13\');',