Both update-lxcs.sh and update-apps.sh backgrounded pct shutdown and then
immediately called pct exec on the same container, causing 'Error: unexpected
status' which terminated the loop after the first container.
update-lxcs.sh: wrapped reboot-required and patchmon-agent checks in a
guard that only runs them when the container was already running (not
one that was started and is now being shut down).
update-apps.sh: moved pct set (resource reset) and the pct exec
reboot-required check to run before pct shutdown is issued.
Fixes#14027
585de1ba0c