Add a new protocol

Co-authored-by: Gérald Croës <gerald@containo.us>

middlewares/customerrors/custom_errors_test.go

@@ -124,7 +124,7 @@ type mockServiceBuilder struct {
 	handler http.Handler
 }
 
-func (m *mockServiceBuilder) Build(_ context.Context, serviceName string, responseModifier func(*http.Response) error) (http.Handler, error) {
+func (m *mockServiceBuilder) BuildHTTP(_ context.Context, serviceName string, responseModifier func(*http.Response) error) (http.Handler, error) {
 	return m.handler, nil
 }