Replace deprecated OpenSSL.crypto.load_crl

Replace deprecated OpenSSL.crypto.load_crl

OpenSSL.crypto.load_crl was deprecated with with pyOpenSSL 23.3.0 and
eventually removed in 24.3.0. pyOpenSSL recommends using cryptography.x509's
CRL functions as a replacement.
See also: https://github.com/pyca/pyopenssl/blob/main/CHANGELOG.rst

Signed-off-by: Christian Schürmann <spike@fedoraproject.org>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <20250704082813.99654-2-spike@fedoraproject.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg32037.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>