Backport two upstream commits that allow building
openvpn-openssl without OpenSSLs deprecated APIs.
Full changelog:
https://community.openvpn.net/openvpn/wiki/ChangesInOpenvpn24#OpenVPN2.4.8
Signed-off-by: Magnus Kroken <mkroken@gmail.com>
(cherry-picked from commit bf43e5bbf91ca1a90df8dae3e2cce6bbb61d5cd9)
