Fix data races
Fix data races

wallyqs/go-nats,nats-io/nats,dnascimento/nats,pires/nats,nats-io/nats,the-control-group/nats,wallyqs/go-nats,apcera/nats,chzyer-dev/nats,wallyqs/nats,dnascimento/nats,the-control-group/nats,nats-io/go-nats,ZebinKang/go-nats,nats-io/go-nats,apcera/nats,pires/nats,ZebinKang/go-nats,gale320/nats,Lanzafame/nats,ActiveState/nats,aforward/nats