Add copyright headers

models/issue_watch.go

@@ -1,3 +1,7 @@
+// Copyright 2017 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 models
 
 import (

routers/repo/issue_watch.go

@@ -1,3 +1,7 @@
+// Copyright 2017 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 repo
 
 import (