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

tests/standalone/io/secure_socket_bad_data_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 
 import "dart:async";
@@ skipping 132 matching lines @@
 Future test(bool hostnameInConnect) {
   return RawServerSocket.bind(HOST_NAME, 0).then((server) {
     server.listen((client) {
       RawSecureSocket.secureServer(client, CERTIFICATE)
         .then((secureClient) {
           Expect.throws(() => client.add([0]));
           return runServer(secureClient);
         },
         onError: (e) {
           Expect.isTrue(e is HandshakeException);
-          Expect.isTrue(e.toString().contains(
-              'received a record with an incorrect Message Authentication'));
         })
         .whenComplete(server.close);
     });
     return connectClient(server.port, hostnameInConnect).then(runClient);
   });
 }
 
 
 main() {
   String certificateDatabase = Platform.script.resolve('pkcert').toFilePath();
   SecureSocket.initialize(database: certificateDatabase,
                           password: 'dartdart',
                           useBuiltinRoots: false);
   asyncStart();
   Future.wait([test(false), test(true)])
       .then((_) => asyncEnd());
 }