While looking at PR100731, I have noticed the copyright years are 2020-ish
only. This patch adds it to update-copyright.py and updates those.
2021-05-25 Jakub Jelinek <jakub@redhat.com>
contrib/
* update-copyright.py: Add c++tools.
c++tools/
* Makefile.in: Update copyright year.
* configure.ac: Likewise.
* resolver.cc: Likewise.
* resolver.h: Likewise.
* server.cc: Likewise.
(print_version): Update copyright notice date.