Don't expect a specific string in a HandshakeException, in secure_socket_bad_data_test.

tests/standalone/io/secure_socket_bad_data_test.dart

Index: tests/standalone/io/secure_socket_bad_data_test.dart
diff --git a/tests/standalone/io/secure_socket_bad_data_test.dart b/tests/standalone/io/secure_socket_bad_data_test.dart
index 27c6724f51b6b5ba9abbab57c5eae9de2b0fc756..bff3f463d8167bd8ce61ac8c6ae8ff51f9fa5e0c 100644
--- a/tests/standalone/io/secure_socket_bad_data_test.dart
+++ b/tests/standalone/io/secure_socket_bad_data_test.dart
@@ -150,8 +150,6 @@ Future test(bool hostnameInConnect) {
         },
         onError: (e) {
           Expect.isTrue(e is HandshakeException);
-          Expect.isTrue(e.toString().contains(
-              'received a record with an incorrect Message Authentication'));
         })
         .whenComplete(server.close);
     });