Discard stale requests in update_destination.
Discard stale requests in update_destination.

Gwendocg/babeldToS,jech/babeld,sudomesh/babeld,jech/babeld,wlanslovenija/babeld,Drooids/babeld,wlanslovenija/babeld,Gwendocg/babeldToS,boutier/babeld,woniullb/babeld,dtaht/babeld-shortrtt-metrics,tcatm/babeld