x/net/http2: remove http2.golang.org references

[davecheney]

https://downforeveryoneorjustme.com/http2.golang.org?proto=https

[davecheney]

Mea culpa, it looks like this service was torn down in #49301

However,

• The domain is still registered
• The documentation at https://pkg.go.dev/golang.org/x/net/http2 references http2.golang.org.

[seankhliao]

Does registered here mean having a DNS record or something else?

[dr2chase]

There's two mentions in the source code as of right now:

git grep http2.golang.org
http2.go:// See https://http2.golang.org/ for a test server running this code.
transport_test.go:      transportHost = flag.String("transporthost", "http2.golang.org", "hostname to use for TestTransport")

@neild, @tombergan, any recommendations? Seems like that test is either always failing or dead code.

[gopherbot]

Change https://go.dev/cl/693895 mentions this issue: http2: remove references to defunct http2.golang.org test server