net/http: update bundled http2
Updates bundled x/net/http2 to git rev
cffdcf67 for:
http2: use GetBody unconditionally on Transport retry, when available
https://golang.org/cl/123476
http2: a closed stream cannot receive data
https://golang.org/cl/111676
Updates #25009
Updates #25023
Change-Id: I84f50cc50c0fa5a3c34f0037a9cb1ef468e5f0d9
Reviewed-on: https://go-review.googlesource.com/123515
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>