Fix AuthPlugin function signature.

MaharaAuthPlugin.php

@@ -236,7 +236,7 @@ class MaharaAuthPlugin extends AuthPlugin {
      *
      * @param $template UserLoginTemplate object.
      */
-    public function modifyUITemplate(&$template) {
+    public function modifyUITemplate(&$template, &$type) {
         # Override this!
         $template->set('usedomain', false);
     }