I had a case when an operator set the timeout too a abnormally large
value, which caused OverflowError in the timeout clean_up task, which,
in turn, prevented ironic-inspector from ever running node list sync
with ironic.
This change makes two corrections:
* The timeout configuration is limited to 10 years (0 can still be used
to disable the timeout completely).
* Errors in the clean_up task do not prevent the node list sync from
running.
Change-Id: Ie3ad29a4abb9ac58c41b776042f80dff6a9c72d2
Story: #2004807
Task: #28963
(cherry picked from commit ab4a3bd867)