Update copyright

Author: Emile Joubert

test/src/com/rabbitmq/client/test/performance/StressManagement.java

@@ -11,7 +11,7 @@
 //  The Original Code is RabbitMQ.
 //
 //  The Initial Developer of the Original Code is VMware, Inc.
-//  Copyright (c) 2007-2012 VMware, Inc.  All rights reserved.
+//  Copyright (c) 2007-2013 VMware, Inc.  All rights reserved.
 //
 
 package com.rabbitmq.client.test.performance;