fix qbittorrent csrf header handling

[aerz]

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• I have read the contributing guideline and understand that I have made the correct modifications

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Description

Fix qBittorrent CSRF 401 behind reverse proxy on v5.2.0+.

Replaces Host $upstream_app:$upstream_port with Host $host and adds Origin "https://$host" so the CSRF check in v5.2.0+ passes. Removes Referer '' (old workaround, no longer needed).

Applied to qbittorrent.subfolder.conf.sample and qbittorrent.subdomain.conf.sample across all location blocks.

How Has This Been Tested?

Tested with SWAG (linuxserver/nginx) proxying linuxserver/qbittorrent v5.2.x. 401 resolved with these headers. Both subfolder and subdomain configs verified working.

References

• Upstream issue that confirms root cause: Reverse proxy configuration doesn't work with 5.2.0 qbittorrent/qBittorrent#24184
• NPM community issue with identical fix: CSRF Token error using Nginx Proxy Manager NginxProxyManager/nginx-proxy-manager#1819
• Related discussion: [BUG] <title> 401 Unauthorized Error when running 4.5.3[latest] docker image docker-qbittorrent#243