Fix const reference for protobuf
Fix const reference for protobuf

dnascimento/nats,apcera/nats,the-control-group/nats,ZebinKang/go-nats,ZebinKang/go-nats,nats-io/go-nats,dnascimento/nats,pires/nats,wallyqs/go-nats,nats-io/nats,wallyqs/go-nats,nats-io/go-nats,pires/nats,apcera/nats,the-control-group/nats,nats-io/nats