pkg/intl: updated for latest unittest deprecations

pkg/intl/test/date_time_format_http_request_test.dart

Index: pkg/intl/test/date_time_format_http_request_test.dart
diff --git a/pkg/intl/test/date_time_format_http_request_test.dart b/pkg/intl/test/date_time_format_http_request_test.dart
index 26bd47688ae1c2484231ef68c40d7639bb9a5986..4e7fa5c0d1d21a4dce8580fd5e906bcdebf657c0 100644
--- a/pkg/intl/test/date_time_format_http_request_test.dart
+++ b/pkg/intl/test/date_time_format_http_request_test.dart
@@ -21,7 +21,7 @@ main() {
     "/root_dart/pkg/intl/lib/src/data/dates/";
 
    test("Initializing a locale that needs fallback", () {
-     initializeDateFormatting("de_DE", url).then(expectAsync1((_) => true));
+     initializeDateFormatting("de_DE", url).then(expectAsync((_) => true));
    });
 
   runWith(smallSetOfLocales, url, initializeDateFormatting);