batman-adv: update copyright years

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

net/batman-adv/icmp_socket.h

@@ -1,4 +1,4 @@
-/* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
+/* Copyright (C) 2007-2013 B.A.T.M.A.N. contributors:
  *
  * Marek Lindner
  *