[Bug] reverse proxy quic/http3 oidc fails

Describe the bug

I just switched on http3/quic on my nginx reverse proxy. This failed on my former working oauth setup to FreshRSS with httpd/quic supporting browsers. Login worked via tor, via a corporate proxy which does not offer quic and browsers which do not support quic. (oauth backend: forgejo)

To Reproduce

1. Have a working oauth setup
2. Reverse Proxy: enable HTTP/3 - Quic
3. Try to open FreshRSS

Expected behavior

Expected:

• (login via the oauth host - in my case forgejo)
• Redirect into FreshRSS

Actual behaviour:

• (login via the oauth host - in my case forgejo)
• Redirect fails. There are different error messages depending on browser. But there are messages like "Redirect Failure", "unexpected oidc host", freshrss.local as target in the redirect url (!) though it is nowhere set...

FreshRSS version

1.28.1

System information

• Database version: SQLite
• PHP version: original Container version
• Installation type: official Container via docker-compose
• Web server type: Reverse: nginx
• Device: Asahi Laptop, Windows Laptop (Corporate - Works!), Android Device
• OS: Debian Testing (asahi), Windows 11, GrapheneOS
• Browser: Firefox 149 (fails), Firefox-ESR (Corporate behind zScaler proxy- Works!), Epiphany 49.2 (Works, probably no Quic-Support in Browser), Fennec 149.0.1 (fails).

Additional context

I could fix it via a proxy_http_version 1.1; directive, so the settings are now:

           location / {
               proxy_http_version 1.1; # <---- the needed option
               proxy_set_header Host $http_host;
               proxy_set_header X-Real-IP $remote_addr;
               proxy_set_header X-Forwarded-For $remote_addr;
               proxy_set_header X-Forwarded-Proto $scheme;
               proxy_set_header X-Forwarded-Host $http_host;
               proxy_pass http://localhost:8080/;
               add_header Alt-Svc 'h3=":443"; ma=86400';
           break;
           }

So it probably needed to be mentioned in the documentation.