add year and copyright owner to GNU v3

Author: fdiblen

template/{% if license == 'GNUv3' %}LICENSE{% endif %}.jinja

@@ -632,7 +632,7 @@ state the exclusion of warranty; and each file should have at least
 the "copyright" line and a pointer to where the full notice is found.
 
     <one line to give the program's name and a brief idea of what it does.>
-    Copyright (C) <year>  <name of author>
+    Copyright (C) {{ '%Y' | strftime }}, {{ copyright_holder }}
 
     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