Update description of SIGUSR1 in man page.
Update description of SIGUSR1 in man page.

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