Remove OpenSSL configure checks

Remove OpenSSL configure checks

These checks for the functions take a lot of time in configure call and
also having these checks make it more blurry for which of the supported
OpenSSL versions (and libraries claiming to be OpenSSL) are actually
needed.

Tested with OpenSSL 1.1.1(Ubuntu 20, macOS), 1.0.2 (CentOS7),
1.1.0 (Debian stretch), LibreSSL (OpenBSD 6.8) and wolfSSL

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Antonio Quartulli <antonio@openvpn.net>
Message-Id: <20210406162518.4075-5-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg22051.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>