Fixed strict warning, only variables should be passed by reference

includes/locale.inc

@@ -619,7 +619,8 @@ function locale_translate_import_form() {
       t('Already added languages') => $names,
       t('Languages not yet added') => _locale_prepare_predefined_list()
     );
-    $default = array_shift(array_keys($names));
+    $keys_names = array_keys($names);
+    $default = array_shift($keys_names);
   }
 
   $form = array();