Upgrade xorm to v0.8.0 (#8536)

vendor/xorm.io/xorm/helpler_time.go

@@ -0,0 +1,21 @@
+// Copyright 2017 The Xorm Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package xorm
+
+import "time"
+
+const (
+	zeroTime0 = "0000-00-00 00:00:00"
+	zeroTime1 = "0001-01-01 00:00:00"
+)
+
+func formatTime(t time.Time) string {
+	return t.Format("2006-01-02 15:04:05")
+}
+
+func isTimeZero(t time.Time) bool {
+	return t.IsZero() || formatTime(t) == zeroTime0 ||
+		formatTime(t) == zeroTime1
+}