If another RPZ update is pending when processing the previous one nears
completion and min-update-interval is set to 0, isc_timer_reset() gets
called with 'interval' set to 0, which triggers an assertion failure.
To prevent such a scenario from causing a crash, queue the update event
directly instead of asking the timer thread to do it.
(cherry picked from commit faf2c7711a)
Witold Kręcicki
384b3ef596