Split migrations folder (#21549)

There are too many files in `models/migrations` folder so that I split
them into sub folders.

models/migrations/v1_8/v79.go

@@ -0,0 +1,26 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package v1_8 // nolint
+
+import (
+	"code.gitea.io/gitea/modules/setting"
+
+	"xorm.io/xorm"
+)
+
+func AddCanCloseIssuesViaCommitInAnyBranch(x *xorm.Engine) error {
+	type Repository struct {
+		ID                              int64 `xorm:"pk autoincr"`
+		CloseIssuesViaCommitInAnyBranch bool  `xorm:"NOT NULL DEFAULT false"`
+	}
+
+	if err := x.Sync2(new(Repository)); err != nil {
+		return err
+	}
+
+	_, err := x.Exec("UPDATE repository SET close_issues_via_commit_in_any_branch = ?",
+		setting.Repository.DefaultCloseIssuesViaCommitsInAnyBranch)
+	return err
+}