ABM action calls are delayed until a background timer picks them
up, but it passes in the original args and assumes that the nodes
haven't changed. In addition, it bypasses our bug #8378 hack,
because that check is done in the abm action call but NOT the
background worker timer.
Do a check in the worker to make sure the node to be acted on has
not changed since the call was queued, and just let the call miss
and waste in that case.
Note that this automatically implicitly handles any #8378 issues
that may still be present since it has to force a fresh check of
the node to be operated on anyway.
7d1d1e9602