Remove stray characters

Author: Emile Joubert

src/com/rabbitmq/client/PossibleAuthenticationFailureException.java

@@ -1,6 +1,6 @@
 //  The contents of this file are subject to the Mozilla Public License
 //  Version 1.1 (the "License"); you may not use this file except in
-//  compliance with the License. You may obtain IOa copy of the License
+//  compliance with the License. You may obtain a copy of the License
 //  at http://www.mozilla.org/MPL/
 //
 //  Software distributed under the License is distributed on an "AS IS"