301 替换 404

apache写法：

RewriteEngine On
RewriteBase /

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ / [R=301,L]

nginx写法：

if (!-f $request_filename){
	set $rule_0 1$rule_0;
}
if (!-d $request_filename){
	set $rule_0 2$rule_0;
}
if ($rule_0 = "21"){
	rewrite ^/(.*)$ / permanent;
	break;
}