Missing argument 2 for variable_get()

http://drupal.org/node/31792

on line 693 second argument was missing, so i just put 0 and it worked

              $subject = '['.variable_get('site_name', 'drupal').']'.t('Notification from subscriptions');
 L693     $from = variable_get("site_mail",0);
              $user = user_load(array('uid' => $uid));