Guard account client map

server/server.go

@@ -1236,6 +1236,7 @@ func (s *Server) registerAccountNoLock(acc *Account) *Account {
 	// Finish account setup and store.
 	s.setAccountSublist(acc)
 
+	acc.mu.Lock()
 	if acc.clients == nil {
 		acc.clients = make(map[*client]struct{})
 	}
@@ -1245,7 +1246,6 @@ func (s *Server) registerAccountNoLock(acc *Account) *Account {
 	// During config reload, it is possible that account was
 	// already created (global account), so use locking and
 	// make sure we create only if needed.
-	acc.mu.Lock()
 	// TODO(dlc)- Double check that we need this for GWs.
 	if acc.rm == nil && s.opts != nil && s.shouldTrackSubscriptions() {
 		acc.rm = make(map[string]int32)