host stack: update stale copyright

Change-Id: I33cd6e44d126c73c1f4c16b2041ea607b4d7f39f
Signed-off-by: Florin Coras <fcoras@cisco.com>
diff --git a/src/vnet/udp/udp_error.def b/src/vnet/udp/udp_error.def
index 488e7be..e9baa33 100644
--- a/src/vnet/udp/udp_error.def
+++ b/src/vnet/udp/udp_error.def
@@ -1,7 +1,7 @@
 /*
  * udp_error.def: udp errors
  *
- * Copyright (c) 2013-2016 Cisco and/or its affiliates.
+ * Copyright (c) 2013-2019 Cisco and/or its affiliates.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at: