TT#61954 Update copyright years

Use canonical copyright entity name for Sipwise.

Change-Id: I99e77774043742e579d57d8a5c3467321a784b81

debian/copyright

@@ -4,7 +4,7 @@ Upstream-Name: kamailio-config-tests
 
 Files: *
 Copyright:
- 2013-2017 Sipwise Development Team <support@sipwise.com>
+ Copyright © 2013-2019 Sipwise GmbH, Austria
 License: GPL-3.0+
  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by