Avoid sending --cipher to clients not supporting NCP

Avoid sending --cipher to clients not supporting NCP

The NCP rework introduced a regression of sending a --cipher
command as part of the push message when the client does not
support NCP. This is is more a cosmetic issue since the client
will log that as warning in the log and ignore it.

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20200717134739.21168-7-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg20437.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>