Update logout.php

Author: zhblue

trunk/web/logout.php

@@ -1,6 +1,6 @@
 <?php
 include("./include/db_info.inc.php");
-session_start();
+@session_start();
 unset($_SESSION[$OJ_NAME . '_' . 'user_id']);
 setcookie($OJ_NAME . "_user", "");
 setcookie($OJ_NAME . "_check", "");