t_server_null: use wait instead of marker files

t_server_null: use wait instead of marker files

By using wait in a more inventive way we can avoid using a marker file
to detect the "server could not be killed gracefully" situation.

Change-Id: Ib385080e1dd1c3046c54e6267db8aa7d5c09e2fb
Signed-off-by: Samuli Seppänen <samuli.seppanen@gmail.com>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20241026092515.30559-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg29664.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>