Httpx includes ipv6 scope in Host header

[elupus]

When requesting http paths with scope as part of the ipv6 address, this should stripped before being added to the http host header since it's fully local feature of the ipv6 stack.

Http over link local addresses is quite common on upnp based announces on link local networks.

Apache for example will reject the request: https://bz.apache.org/bugzilla/show_bug.cgi?id=35122
Lighthttpd: https://redmine.lighttpd.net/issues/2442

Example to reproduce:

import httpx
import respx

@respx.mock
def test_example():
    my_route = respx.get("https://[fe80::8fd:8e9a:40d8:29a6%en0]/get")
    my_route.mock(return_value=httpx.Response(204))

    r = httpx.get(r'https://[fe80::8fd:8e9a:40d8:29a6%en0]/get')

    print(my_route.calls[0].request.headers["host"])
    assert my_route.calls[0].request.headers["host"] == "[fe80::8fd:8e9a:40d8:29a6]"

test_example()

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• Initially raised as discussion #...

[elupus]

Ok. I must admit I'm a bit unsure of current RFC status regarding this. Se discussion here: https://bugs.python.org/issue23448