net/http: update bundled http2
Updates http2 to x/net/http2 git rev
97aa3a539 for:
http2: dynamic table updates must occur first
https://golang.org/cl/111681
http2: receiving too much data is a protocol error
https://golang.org/cl/111679
http2: correct overflow protection
https://golang.org/cl/111675
http2: make Server send GOAWAY if Handler sets "Connection: close" header
https://golang.org/cl/121415
Fixes #20977
Change-Id: I9b8659b5191409ed007e2d911913763bcbabb7cc
Reviewed-on: https://go-review.googlesource.com/121695
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>