regarding the nginx configuration

[jeansalim]

I was checking the nginx config.
Why did you use proxy_pass http://${host};
instead of proxy_pass http://$host$request_uri;

and does this directive affect anything?
proxy_set_header Upgrade-Insecure-Requests "";

[jeansalim]

Also, is there and advantage for using proxy_http_version 1.1; over proxy_http_version 1.0?
thanks a lot for the great job you did.