update devops flywau image for arm

Signed-off-by: Nrunzexia <runzexia@yunify.com>

pkg/db/Dockerfile

-# Copyright 2017 The OpenPitrix Authors. All rights reserved.
+# Copyright 2017 The KubeSphere Authors. All rights reserved.
 # Use of this source code is governed by a Apache license
 # that can be found in the LICENSE file.
 
-FROM dhoer/flyway:5.1.4-mysql-8.0.11-alpine
+FROM openpitrix/flyway:alpine
+
+USER root
 
 RUN apk add --no-cache mysql-client