chore(queue): show message if worker numbers big than zero

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

Author: appleboy

queue.go

@@ -90,7 +90,10 @@ func (q *Queue) Shutdown() {
 		return
 	}
 
-	q.logger.Infof("shutdown all woker numbers: %d", q.runningWorkers)
+	if q.runningWorkers > 0 {
+		q.logger.Infof("shutdown all woker numbers: %d", q.runningWorkers)
+	}
+
 	q.stopOnce.Do(func() {
 		if err := q.worker.Shutdown(); err != nil {
 			q.logger.Error(err)