net/http: eliminate the needless idle timeout for TestServerNoReadTimeout

Change-Id: I1339749bfeac99848beca780cebb9c87564da656
Reviewed-on: https://go-review.googlesource.com/c/go/+/573335
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Damien Neil <[email protected]>
Reviewed-by: David Chase <[email protected]>
Reviewed-by: Emmanuel Odeke <[email protected]>

Author: panjf2000

src/net/http/serve_test.go

@@ -814,7 +814,6 @@ func testServerNoReadTimeout(t *testing.T, mode testMode) {
 			res.Write([]byte(resBody))
 		}), func(ts *httptest.Server) {
 			ts.Config.ReadTimeout = timeout
-			ts.Config.IdleTimeout = 10 * time.Millisecond
 			t.Logf("Server.Config.ReadTimeout = %d", timeout)
 		})