Update the NOTICE file to 2010

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/net/branches/NET_2_0@923723 13f79535-47bb-0310-9956-ffa450edef68

Author: Niall Pemberton

NOTICE.txt

@@ -1,5 +1,5 @@
 Apache Commons Net
-Copyright 2001-2009 The Apache Software Foundation
+Copyright 2001-2010 The Apache Software Foundation
 
 This product includes software developed by
 The Apache Software Foundation (http://www.apache.org/).