* change for zh-tw lang.

module/backup/config.php

@@ -1,2 +1,3 @@
 <?php
+$config->backup = new stdclass();
 $config->backup->holdDays = 14;

module/backup/lang/zh-tw.php

@@ -5,6 +5,8 @@ $lang->backup->history  = '備份歷史';
 $lang->backup->delete   = '刪除備份';
 $lang->backup->backup   = '備份';
 $lang->backup->restore  = '還原';
+$lang->backup->change   = '修改保留時間';
+$lang->backup->changeAB = '修改';
 
 $lang->backup->name  = '檔案名稱';
 $lang->backup->time  = '備份時間';
@@ -14,6 +16,7 @@ $lang->backup->size  = '大小';
 $lang->backup->waitting       = '<span id="backupType"></span>正在進行中，請稍候...';
 $lang->backup->confirmDelete  = '是否刪除備份？';
 $lang->backup->confirmRestore = '是否還原該備份？';
+$lang->backup->holdDays       = '備份保留最近 %s 天';
 
 $lang->backup->success = new stdclass();
 $lang->backup->success->backup  = '備份成功！';