Update copyright dates, to include 2015.  No functional change.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15577 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/drd/drd_thread_bitmap.h b/drd/drd_thread_bitmap.h
index 7687c02..dce884e 100644
--- a/drd/drd_thread_bitmap.h
+++ b/drd/drd_thread_bitmap.h
@@ -1,7 +1,7 @@
 /*
   This file is part of drd, a thread error detector.
 
-  Copyright (C) 2006-2013 Bart Van Assche <bvanassche@acm.org>.
+  Copyright (C) 2006-2015 Bart Van Assche <bvanassche@acm.org>.
 
   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as