refactor: openpitrix module

Signed-off-by: hongming <talonwan@yunify.com>

vendor/openpitrix.io/openpitrix/pkg/constants/user.go

@@ -0,0 +1,11 @@
+// Copyright 2018 The OpenPitrix Authors. All rights reserved.
+// Use of this source code is governed by a Apache license
+// that can be found in the LICENSE file.
+
+package constants
+
+const UserSystem = "system"
+
+var InternalUsers = []string{
+	UserSystem,
+}