Allow more than 255 characters for tokens in external_login_user table (#8554)

Signed-off-by: Wenxuan Zhao <viz@linux.com>

models/migrations/v101.go

@@ -0,0 +1,19 @@
+// 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 migrations
+
+import (
+	"xorm.io/xorm"
+)
+
+func changeSomeColumnsLengthOfExternalLoginUser(x *xorm.Engine) error {
+	type ExternalLoginUser struct {
+		AccessToken       string `xorm:"TEXT"`
+		AccessTokenSecret string `xorm:"TEXT"`
+		RefreshToken      string `xorm:"TEXT"`
+	}
+
+	return x.Sync2(new(ExternalLoginUser))
+}