[gardening] fix retries in socket_source_address_test

Change-Id: I05bd349a039092d0a7839f04f40b4c4561611bbb
Reviewed-on: https://dart-review.googlesource.com/c/84036
Auto-Submit: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
diff --git a/tests/standalone_2/io/socket_source_address_test.dart b/tests/standalone_2/io/socket_source_address_test.dart
index 236733a..82f5099 100644
--- a/tests/standalone_2/io/socket_source_address_test.dart
+++ b/tests/standalone_2/io/socket_source_address_test.dart
@@ -29,8 +29,13 @@
 
   var sourceAddress;
   asyncStart();
-  var server =
-      await ServerSocket.bind(InternetAddress.loopbackIPv4, freePort);
+  var server;
+  try {
+    server = await ServerSocket.bind(InternetAddress.loopbackIPv4, freePort);
+  } catch (e) {
+    asyncEnd();
+    rethrow;
+  }
   server.listen((_) {
     throw 'Unexpected connection from address $sourceAddress';
   }, onDone: () => asyncEnd());