server: Update copyright after zmq changes

Change-Id: I8861acaaec5465de620637b7fdf3341517133c4f
diff --git a/src/osmo_server_network.c b/src/osmo_server_network.c
index 8d41eaf..22af2b4 100644
--- a/src/osmo_server_network.c
+++ b/src/osmo_server_network.c
@@ -1,7 +1,7 @@
 /*
  * osmo-pcap-server code
  *
- * (C) 2011-2017 by Holger Hans Peter Freyther <holger@moiji-mobile.com>
+ * (C) 2011-2016 by Holger Hans Peter Freyther <holger@moiji-mobile.com>
  * (C) 2011 by On-Waves
  * All Rights Reserved
  *