Don't use legacy method to send Matrix Webhook (#12348)

* Don't use legacy send for messages

* Add migrations to ensure Matrix webhooks use PUT

* Set HTTP method to PUT as default

* Fix sql condition..

Signed-off-by: Till Faelligen <tfaelligen@gmail.com>

* Rename getTxnID -> getMatrixTxnID

* Use local variable instead of constant value

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

models/migrations/v144.go

@@ -0,0 +1,25 @@
+// Copyright 2020 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 (
+	"code.gitea.io/gitea/modules/log"
+	"xorm.io/builder"
+	"xorm.io/xorm"
+)
+
+func updateMatrixWebhookHTTPMethod(x *xorm.Engine) error {
+	var matrixHookTaskType = 9 // value comes from the models package
+	type Webhook struct {
+		HTTPMethod string
+	}
+
+	cond := builder.Eq{"hook_task_type": matrixHookTaskType}.And(builder.Neq{"http_method": "PUT"})
+	count, err := x.Where(cond).Cols("http_method").Update(&Webhook{HTTPMethod: "PUT"})
+	if err == nil {
+		log.Debug("Updated %d Matrix webhooks with http_method 'PUT'", count)
+	}
+	return err
+}