h2 always reported in alpn_protocols

[Diggsey]

axum-server/src/tls_rustls/mod.rs

Line 278 in 86bc6e7

config.alpn_protocols = vec![b"h2".to_vec(), b"http/1.1".to_vec()];

This is wrong as the axum server doesn't necessarily support http2.

[daxpedda]

I don't think there is currently a way for axum-server to not serve both protocols HTTP/2.
Internally Builder::serve_connection_with_upgrades() is used, so e.g. no matter if you use Builder::http2_only(), both HTTP/1 and HTTP/2 will be served.

Let me know if I'm wrong about that.