Send AUTH_FAILED message to clients on renegotiation failures

Send AUTH_FAILED message to clients on renegotiation failures

This changes the exit in server mode on renegotiation to an exit that
also sends an AUTH_FAILED to the client. Any previously set failed auth
reason is passed to the client.

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20201023120259.29783-6-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg21222.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>