net/http: update bundled http2
net/http: update bundled http2

Updates bundled http2 to x/net git rev ed066c81e7 for:

    http2: Revert a closed stream cannot receive data
    https://golang.org/cl/153977

Updates golang/go#28204

Change-Id: I0a489e4e8a581a107970199f64f0fa9281982efe
Reviewed-on: https://go-review.googlesource.com/c/159179
Run-TryBot: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Dmitri Shuralyov <d181b7fea0ec87c86ba5a890ab716db52498e3ba@golang.org>

josharian/go,golang/go,cloudflare/go,akutz/go,cloudflare/go,josharian/go,golang/go,golang/go,nawawi/go,nawawi/go,cloudflare/go,akutz/go,josharian/go,josharian/go,akutz/go,nawawi/go,cloudflare/go,golang/go,CAFxX/go,nawawi/go,josharian/go,nawawi/go,akutz/go,CAFxX/go,golang/go,CAFxX/go,CAFxX/go,nawawi/go,golang/go,nawawi/go,akutz/go,cloudflare/go,cloudflare/go,CAFxX/go,akutz/go,nawawi/go,josharian/go,josharian/go,akutz/go,CAFxX/go,akutz/go,CAFxX/go,CAFxX/go,josharian/go,golang/go,golang/go,cloudflare/go,cloudflare/go