signal --dns support in peer info

signal --dns support in peer info

Have clients set a bit in IV_PROTO, so that servers can make an informed
decision on whether to push --dns to the client. While unknown options
are ignored by clients when pushed, they generate a warning in the log.
That can be circumvented by server backends by checking if bit 7 is set.

Signed-off-by: Heiko Hund <heiko@ist.eigentlich.net>
Acked-by: David Sommerseth <davids@openvpn.net>
Message-Id: <20220513093740.1091639-1-heiko@ist.eigentlich.net>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg24350.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>