Add ProxyProtocol Support

### Welcome! - [x] Yes, I've searched similar issues on [GitHub](https://github.com/traefik/whoami/issues) and didn't find any. ### What did you expect to see? [ProxyProtocol via 3.5.2 real ip address no longer works](https://github.com/traefik/traefik/issues/12055) With ProxyProtocol support to test with traefik