主机宝linux怎么取消ip访问默认页面

server {
            listen       80 default;
            server_name  "";

            root /a/apps/zhujibao/manager/linuxdef;
                index index.html index.htm index.shtml index.php;

                location ~ \.php$ {
                        fastcgi_pass   unix:/dev/shm/php.sock;
                        include        fastcgi_params;
                        fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
                }    
        }  


可以改为：

server {
            listen       80 default;
            server_name  "";

             return 404;

            root /a/apps/zhujibao/manager/linuxdef;
                index index.html index.htm index.shtml index.php;

                location ~ \.php$ {
                        fastcgi_pass   unix:/dev/shm/php.sock;
                        include        fastcgi_params;
                        fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
                }    
        }  

怎么我删除了还是不行