Add the following line to /etc/pve/lxc/XXXX.conf at your hostnode.
Code:
lxc.hook.stop: sh -c "pct mount ${LXC_NAME}; perl -pi -w -e 's/^(\/sbin\/start_udev)/# \$1/g' /var/lib/lxc/${LXC_NAME}/rootfs/etc/rc.d/rc.sysinit; pct unmount ${LXC_NAME}"
This hook will be executed after a VPS stop. The code mounts the VPS filesystem, does some regexp magic on rc.sysinit (commenting /sbin/start_udev) and unmounts the VPS filesystem.
I'm assuming the update of the initscripts only become active after a VPS is stopped and started from the hostnode (e.g. pct stop/start)
So entering the command "reboot" from within the VPS won't work. In my findings the VPS even doesn't come up.... I think "lxc.hook.stop" is used by Proxmox itself and we can't "enqueue" to it.