fix: return error for invalid device token removal

Author: Finb

route_push.go

@@ -264,6 +264,7 @@ func push(params map[string]interface{}) (int, error) {
 	// Remove deviceToken if it’s too long, to clean up junk data.
 	if len(deviceToken) > 128 {
 		_ = db.DeleteDeviceByKey(msg.DeviceKey)
+		return 400, fmt.Errorf("invalid device token, has been removed")
 	}
 
 	msg.DeviceToken = deviceToken