discuz x3.1 去除后头的portal.php

修改index.php文件代码 查找代码：  

$url = empty($_ENV['domain']['app']['default']) ? (!empty($_ENV['domain']['defaultindex']) ? $_ENV['domain']['defaultindex'] : 'forum.php') : 'http://'.$_ENV['domain']['app']['default'];
 改为：   $_ENV['curapp'] = str_replace('.php', '', $_ENV['domain']['defaultindex']);