Update rustls to v0.22

[zehnm]

Rustls 0.22 has been released a month ago. We should upgrade.
Maybe this fixes the connection issue to Traefik, reported in:

• [bug] HomeAssitant SSL Support feature-and-bug-tracker#189

However, 0.22 has major breaking changes and it won't be a simple crate update.
Furthermore, we can't upgrade yet because actix-web, awc and actix-tls only support rustls 0.21 as of now.

This already happened when upgrading to 0.21 - maybe we should consider switching to rust-openssl?
Even though I really like the full Rust approach, those breaking changes are becoming a hassle.