Add the SCRIPT_FILENAME variable in the vhost

conf/nginx_vpnadmin.conf

@@ -34,6 +34,7 @@ location <TPL:NGINX_LOCATION> {
     fastcgi_read_timeout 600;
     fastcgi_param REMOTE_USER $remote_user;
     fastcgi_param PATH_INFO $fastcgi_path_info;
+    fastcgi_param SCRIPT_FILENAME $request_filename;
   }
 
   include conf.d/yunohost_panel.conf.inc;