First real run returned empty and we had no idea why — the script was
silently swallowing stderr via `2>/dev/null`. Remove the suppression
and try both `execute dhcp lease-list all` and the no-arg form, keeping
whichever returns non-error output.
Also emit a clearer diagnostic when both fail, pointing the user at
an interactive SSH to poke at command syntax.
vh
83eddc872a