Fix problems with NCP and --inetd.

Fix problems with NCP and --inetd.

NCP only works with --pull or --mode server, leading to breakage
in --inetd mode (because that has --tls-server, but not --mode server,
but clients can still ask for PUSH_REQUEST).

Fix by turning off o->ncp_enable unless (pull or mode server), and
double-fix by logging an appropriate message and refusing to change
ciphers if the server has already set up its keys.

v2: wrap long msg() text lines

Trac: 715
Signed-off-by: Gert Doering <gert@greenie.muc.de>
Acked-by: Steffan Karger <steffan@karger.me>
Message-Id: 1471897487-8354-1-git-send-email-gert@greenie.muc.de
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg00060.html
Signed-off-by: David Sommerseth <davids@openvpn.net>