Use mod vendor for vendored directory (backwards compatible)

vendor/github.com/mattermost/mattermost-server/model/channel_search.go

@@ -1,26 +0,0 @@
-// Copyright (c) 2016-present Mattermost, Inc. All Rights Reserved.
-// See License.txt for license information.
-
-package model
-
-import (
-	"encoding/json"
-	"io"
-)
-
-type ChannelSearch struct {
-	Term string `json:"term"`
-}
-
-// ToJson convert a Channel to a json string
-func (c *ChannelSearch) ToJson() string {
-	b, _ := json.Marshal(c)
-	return string(b)
-}
-
-// ChannelSearchFromJson will decode the input and return a Channel
-func ChannelSearchFromJson(data io.Reader) *ChannelSearch {
-	var cs *ChannelSearch
-	json.NewDecoder(data).Decode(&cs)
-	return cs
-}