Fix pub after changing the HttpServer.bind signature

pkg/scheduled_test/lib/src/scheduled_server/safe_http_server.dart

Index: pkg/scheduled_test/lib/src/scheduled_server/safe_http_server.dart
diff --git a/pkg/scheduled_test/lib/src/scheduled_server/safe_http_server.dart b/pkg/scheduled_test/lib/src/scheduled_server/safe_http_server.dart
index b6e1c83a3adfa21c3544fc1957a69fccbcdb25cf..2c193681045583de7d9e94263bb34495f5167576 100644
--- a/pkg/scheduled_test/lib/src/scheduled_server/safe_http_server.dart
+++ b/pkg/scheduled_test/lib/src/scheduled_server/safe_http_server.dart
@@ -23,7 +23,7 @@ class SafeHttpServer extends StreamView<HttpRequest> implements HttpServer {
 
   static Future<SafeHttpServer> bind([String host = "127.0.0.1",
       int port = 0, int backlog = 0]) {
-    return HttpServer.bind(host, port, backlog)
+    return HttpServer.bind(host, port, backlog: backlog)
         .then((server) => new SafeHttpServer(server));
   }