HTTP/1.0 support

[Shnatsel]

On some websites, e.g. http://thomsonreuters.co.uk, surf fails with the following error:

Unsupported HTTP version

Firefox, curl and ureq (a blocking Rust client) work fine.

11820 websites out of the top million from Feb 3 Tranco list are affected.

Tested using this code. Test tool output from all affected websites: surf-unsupported-http-version.tar.gz

I've only tested the async-h1 backend; I don't know if the other backends are affected.

[Fishrock123]

async-h1 is a HTTP 1.1 parser.

Opt-in HTTP 1.0 support was recently-ish merged however, but you'll need to set that up yourself: http-rs/async-h1#170

That is server-only, there is no client support presently.

[Shnatsel]

It would be nice to expose this option in surf and accept HTTP 1.0 by default, since literally every other client I've tested seems to do so.

[Fishrock123]

(Note, this is barely over 1% of websites.)

It's of low importance to newer HTTP clients, but we may have an option to support it depending what implications it has.

[d4h0]

I've only tested the async-h1 backend; I don't know if the other backends are affected.

At least with the hyper backend, this problem doesn't seem to exist:

$ longboard -c h1 GET http://thomsonreuters.co.uk
Error: Unsupported HTTP version

$ longboard -c hyper GET http://thomsonreuters.co.uk
─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
response headers
─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
{
    "content-type": "application/octet-stream",
    "server": "BigIP",
    "connection": "Keep-Alive",
    "location": "http://www.thomsonreuters.co.uk/",
    "content-length": "0",
}
─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
status
─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
301: Moved Permanently
─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
response body (application/octet-stream)   <EMPTY>

It's of low importance to newer HTTP clients, but we may have an option to support it depending what implications it has.

To me, it seems like a big problem if 1% of all websites won't work with surf/h1. Basically, there is a 1% chance that I have to rewrite my code and use a different library, if I use async-std and surf (I use tokio and surf/hyper, so it's not a problem for me personally)