Remove deprecated second argument to SendPort.send().

tests/standalone/io/http_advanced_test.dart

Index: tests/standalone/io/http_advanced_test.dart
diff --git a/tests/standalone/io/http_advanced_test.dart b/tests/standalone/io/http_advanced_test.dart
index 63a3be8128f9dde071ee9e382bf1525ff3a28937..1c42e5e2280f18c422ab4f8cac1eb6447447aa30 100644
--- a/tests/standalone/io/http_advanced_test.dart
+++ b/tests/standalone/io/http_advanced_test.dart
@@ -219,16 +219,15 @@ class TestServer {
         HttpServer.bind("127.0.0.1", 0).then((server) {
           _server = server;
           _server.listen(_requestReceivedHandler);
-          replyTo.send(new IsolatedHttpServerStatus.started(_server.port),
-                       null);
+          replyTo.send(new IsolatedHttpServerStatus.started(_server.port));
         });
       } catch (e) {
-        replyTo.send(new IsolatedHttpServerStatus.error(), null);
+        replyTo.send(new IsolatedHttpServerStatus.error());
       }
     } else if (command.isStop) {
       _server.close();
       _dispatchPort.close();
-      replyTo.send(new IsolatedHttpServerStatus.stopped(), null);
+      replyTo.send(new IsolatedHttpServerStatus.stopped());
     } else if (command.isChunkedEncoding) {
       _chunkedEncoding = true;
     }