sample-keys: renew for the next 10 years

sample-keys: renew for the next 10 years

Old expiration was October 2024, less than a year away.
Give everyone the chance to get the new keys before tests
start failing.

Change-Id: Ie264ec1ec61fd71e8cc87987be3e2adc2735c201
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.com>
Message-Id: <20231121110430.16893-1-frank@lichtenheld.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg27530.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit 78e0c5f2f57a18e8ea60951696a458a4b3ff3621)