Incorrect documentation about HTTP/1.1 support

[leewillis77]

The initial set of comments in wp-includes/class-http.php states:

"Handles [...] chunk decoding, if HTTP 1.1"
​http://core.trac.wordpress.org/browser/trunk/src/wp-includes/class-http.php#L5

However, later on, the comments claim "Version 1.1 is not supported, because of chunk response"
​http://core.trac.wordpress.org/browser/trunk/src/wp-includes/class-http.php#L58

I think that 1.1 is supported, as is chunk decoded - ​http://core.trac.wordpress.org/browser/trunk/src/wp-includes/class-http.php#L469

If that's the case, then the documentation should be updated as per the attached patch.

[leewillis77]

Documentation update patch

[dd32]

The docs are wrong, yet, right at the same time.
We don't support HTTP/1.1 since it's untested and mostly broken.
We support chunked decoding, but it's broken, so we don't actually "support" it.

This really goes hand-in-hand with #23463

[dd32]

In 25154:

WP_HTTP: Update the documentation regarding HTTP/1.1 support. Props leewillis77 Fixes #25074