/**
  * remove not installed cronjobs
  */
 private function cronRemove()
 {
     // check user permissions
     if (Yii::app()->user->pbac('userGroups.admin.admin')) {
         // load the cronjobs
         UGCron::init();
         UGCron::add(new UGCJGarbageCollection());
         UGCron::add(new UGCJUnban());
         foreach (Yii::app()->controller->module->crons as $c) {
             UGCron::add(new $c());
         }
         // load the cronjobs
         $crons = UserGroupsCron::model()->findAll();
         foreach ($crons as $c) {
             if (UGCron::getStatus($c->name) === UGCron::NOT_INSTALLED) {
                 $c->delete();
             }
         }
         Yii::app()->user->setFlash('crons', Yii::t('userGroupsModule.admin', 'Cron Jobs successfully removed'));
     } else {
         Yii::app()->user->setFlash('crons', Yii::t('userGroupsModule.admin', 'You are not allowed to remove cron jobs'));
     }
     $this->redirect(Yii::app()->baseUrl . '/userGroups/admin');
 }