Fix retry count in push notifications

In some instances the retry mechanism would get into a busy loop.
That's due to the fact that we would fetch some non-retriable
notifications but not act on them.

This commit fixes the issue by filtering them from the database query
and making sure that we at least wait 1 second.

protocol/pushnotificationclient/client.go

@@ -1425,6 +1425,8 @@ func (c *Client) resendingLoop() error {
 			return nil
 		}
 
+		c.config.Logger.Debug("have some retriable notifications", zap.Int("retryable-notifications", len(retriableNotifications)))
+
 		for _, pn := range retriableNotifications {
 
 			// check if we should retry the notification
@@ -1443,8 +1445,15 @@ func (c *Client) resendingLoop() error {
 		}
 
 		nextRetry := lowestNextRetry - time.Now().Unix()
+
+		// Give some room, sleep at least a second
+		if nextRetry < 1 {
+			nextRetry = 1
+		}
+
 		// how long should we sleep for?
 		waitFor := time.Duration(nextRetry)
+
 		select {
 
 		case <-time.After(waitFor * time.Second):

protocol/pushnotificationclient/persistence.go

@@ -309,7 +309,7 @@ func (p *Persistence) UpdateNotificationResponse(messageID []byte, response *pro
 
 func (p *Persistence) GetRetriablePushNotifications() ([]*SentNotification, error) {
 	var notifications []*SentNotification
-	rows, err := p.db.Query(`SELECT retry_count, last_tried_at, error, success, public_key, installation_id, message_id,chat_id, notification_type FROM push_notification_client_sent_notifications WHERE NOT success AND error = ?`, protobuf.PushNotificationReport_WRONG_TOKEN)
+	rows, err := p.db.Query(`SELECT retry_count, last_tried_at, error, success, public_key, installation_id, message_id,chat_id, notification_type FROM push_notification_client_sent_notifications WHERE NOT success AND error = ? AND retry_count <= ?`, protobuf.PushNotificationReport_WRONG_TOKEN, maxPushNotificationRetries)
 	if err != nil {
 		return nil, err
 	}