Error out if both remap-usr1 SIGHUP and config stdin are used

Error out if both remap-usr1 SIGHUP and config stdin are used

OpenVPN for Android uses config stdin to avoid writing the config
file containing private keys to 'disk'. However using stdin means
that config cannot be reread using SIGHUP. While there might be other
corner cases that trigger SIGHUP, this is an obvious one, so we
error out if we detect this misconfiguration.

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20220722130224.2442759-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg24720.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>