nginx subpath support

[phuslu]

Hi there,

Currently I have a workaround/hacked nginx.conf could proxy spdf in subpath

    location ~ /spdf/ {
        proxy_pass http://127.0.0.1:8080;
        proxy_http_version 1.1;
        rewrite /spdf/(.*) /$1  break;
        sub_filter 'href="/apple-touch-icon.png' 'href="/spdf/apple-touch-icon.png';
        sub_filter 'href="/favicon-32x32.png' 'href="/spdf/favicon-32x32.png';
        sub_filter 'href="/favicon-16x16.png' 'href="/spdf/favicon-16x16.png';
        sub_filter 'href="/site.webmanifest' 'href="/spdf/site.webmanifest';
        sub_filter 'href="/safari-pinned-tab.svg' 'href="/spdf/safari-pinned-tab.svg';
        sub_filter 'href="/favicon.ico' 'href="/spdf/favicon.ico';
        sub_filter 'href="/pdfjs/css/' 'href="pdfjs/css/';
        sub_filter 'action="/' 'action="/spdf/';
        sub_filter_once off;
        proxy_redirect https://phus.lu/ https://phus.lu/spdf/;
        proxy_set_header Host $http_host;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection Upgrade;
    }

As we seen, it's a bit hacky and risky -- although it's the only workable way -- I write it down here for guys who need it.

Could spdf consider add official subpath proxy support?