eliminate data race in NumNodes
eliminate data race in NumNodes

jsternberg/memberlist,atomx/memberlist,oldmantaiter/memberlist,rbg/memberlist,oldmantaiter/memberlist,rbg/memberlist,42wim/memberlist,42wim/memberlist,aybabtme/memberlist,jsternberg/memberlist,hashicorp/memberlist,aybabtme/memberlist,hashicorp/memberlist,atomx/memberlist