[backport] fix(whatsapp): allow registration server to HTTP-fail (#1001)

This diff backports 1f952b5.

Like we did for whatsapp web, we care about doing a TLS handshake
and getting an HTTP response but we don't care about the content
because it may change and that would cause a false positive.

Closes ooni/probe#2384

internal/engine/experiment/whatsapp/whatsapp.go

@@ -25,7 +25,7 @@ const (
 	WebHTTPSURL = "https://web.whatsapp.com/"
 
 	testName    = "whatsapp"
-	testVersion = "0.10.0"
+	testVersion = "0.11.0"
 )
 
 var endpointPattern = regexp.MustCompile(`^tcpconnect://e[0-9]{1,2}\.whatsapp\.net:[0-9]{3,5}$`)
@@ -154,7 +154,6 @@ func (m Measurer) Run(
 		}
 	}
 	inputs = append(inputs, urlgetter.MultiInput{
-		Config: urlgetter.Config{FailOnHTTPError: true},
 		Target: RegistrationServiceURL,
 	})
 	inputs = append(inputs, urlgetter.MultiInput{

internal/engine/experiment/whatsapp/whatsapp_test.go

@@ -20,7 +20,7 @@ func TestNewExperimentMeasurer(t *testing.T) {
 	if measurer.ExperimentName() != "whatsapp" {
 		t.Fatal("unexpected name")
 	}
-	if measurer.ExperimentVersion() != "0.10.0" {
+	if measurer.ExperimentVersion() != "0.11.0" {
 		t.Fatal("unexpected version")
 	}
 }
@@ -336,7 +336,6 @@ func TestWeConfigureWebChecksCorrectly(t *testing.T) {
 	}
 	called := &atomicx.Int64{}
 	emptyConfig := urlgetter.Config{}
-	configWithFailOnHTTPError := urlgetter.Config{FailOnHTTPError: true}
 	measurer := whatsapp.Measurer{
 		Config: whatsapp.Config{},
 		Getter: func(ctx context.Context, g urlgetter.Getter) (urlgetter.TestKeys, error) {
@@ -348,7 +347,7 @@ func TestWeConfigureWebChecksCorrectly(t *testing.T) {
 				}
 			case whatsapp.RegistrationServiceURL:
 				called.Add(4)
-				if diff := cmp.Diff(g.Config, configWithFailOnHTTPError); diff != "" {
+				if diff := cmp.Diff(g.Config, emptyConfig); diff != "" {
 					panic(diff)
 				}
 			default: