net/http: update bundled http2
Update bundled x/net/http2 to x/net git rev
6c4ac8bd for:
http2: fix Transport race sending RST_STREAM while reading DATA on cancels
https://golang.org/cl/32571
http2: remove h2-14 ALPN proto
https://golang.org/cl/32576
Fixes #16974
Change-Id: I6ff8493a13d2641499fedf33e8005004735352ff
Reviewed-on: https://go-review.googlesource.com/32578
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>