Small but important tweaks to fix the operation of the nut initscripts
and hotplug scripts.  All hail shellcheck and proofreading and
dogfooding.

Signed-off-by: Daniel F. Dickinson <cshored@thecshore.com>

Leading zeroes left in ProductId results in some UPS hardware not being matched
by the hotplug script lead to bad permissions and driver not starting.

Closes: #6966
Signed-off-by: Daniel F. Dickinson <cshored@thecshore.com>

usbhid-ups has the necessary information in the source, so
let's support USB hotplugging out of the box.  Takes advantage of
the procd support now in nut-server initscript.

Signed-off-by: Daniel F. Dickinson <cshored@thecshore.com>