easy-rsa not compatible with libressl
https://github.com/OpenVPN/easy-rsa/issues/76
(from redmine: issue id 6477, created on 2016-11-22, closed on 2019-01-23)
https://github.com/OpenVPN/easy-rsa/issues/76
(from redmine: issue id 6477, created on 2016-11-22, closed on 2019-01-23)