Extend the in_array() check with "access denied" option in default_actions() of views_handler_argument_null handler

We should extend the in_array() check with "access denied" option in default_actions() method of views_handler_argument_null handler

  function default_actions($which = NULL) {
    if ($which) {
      if (in_array($which, array('ignore', 'not found', 'empty', 'default', 'access denied'))) {
        return parent::default_actions($which);
      }
      return;
    }
    $actions = parent::default_actions();
    unset($actions['summary asc']);
    unset($actions['summary desc']);
    return $actions;
  }

The parent - views_handler_argument - contain this default action so we can freely delegate the execution to it by calling parent::default_actions($which);