Update mattermost vendor (3.7 => 4.1)

vendor/github.com/mattermost/platform/model/mfa_secret.go

@@ -0,0 +1,34 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package model
+
+import (
+	"encoding/json"
+	"io"
+)
+
+type MfaSecret struct {
+	Secret string `json:"secret"`
+	QRCode string `json:"qr_code"`
+}
+
+func (me *MfaSecret) ToJson() string {
+	b, err := json.Marshal(me)
+	if err != nil {
+		return ""
+	} else {
+		return string(b)
+	}
+}
+
+func MfaSecretFromJson(data io.Reader) *MfaSecret {
+	decoder := json.NewDecoder(data)
+	var me MfaSecret
+	err := decoder.Decode(&me)
+	if err == nil {
+		return &me
+	} else {
+		return nil
+	}
+}