net/http: Connection:close test is h1 specific

Change-Id: I77e4df7ab0bc20d2e251c1eda9ce9026484b8bbc
Reviewed-on: https://go-review.googlesource.com/17433Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/net/http/transport_test.go

@@ -260,6 +260,7 @@ func TestTransportConnectionCloseOnRequest(t *testing.T) {
 
 // if the Transport's DisableKeepAlives is set, all requests should
 // send Connection: close.
+// HTTP/1-only (Connection: close doesn't exist in h2)
 func TestTransportConnectionCloseOnRequestDisableKeepAlive(t *testing.T) {
 	defer afterTest(t)
 	ts := httptest.NewServer(hostPortHandler)