Possibly we should allow HTTP/1.1 CONNECT requests without a Host: header

[njsmith]

According to the spec, all HTTP/1.1 requests MUST have a Host: header. Currently h11 enforces this.

@jab pointed me to this issue that go ran into in 2017 trying to enforce this, where apparently some widespread apps (like Facebook on iOS) do HTTP/1.1 CONNECT without a Host: header: golang/go#18215

It's not entirely clear if this is still relevant 3 years later, but since it's an obscure issue I wanted to make a note somewhere so we can (at the least) find it later.

[balki]

(slightly unrelated). I think the 'Request' class should take a 'host' parameter and include the header automatically. The library anyways checks for it and raises exception, so why not get the host and add the header automatically?

[sigmavirus24]

@balki probably better to open a separate issue for that as it's entirely orthogonal to this issue