[#129] tree: Do not remove tree if the netmap is empty

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

pkg/services/tree/sync.go

@@ -288,7 +288,6 @@ func (s *Service) syncLoop(ctx context.Context) {
 					s.log.Error("could not calculate container nodes",
 						zap.Stringer("cid", cnr),
 						zap.Error(err))
-					removed = append(removed, cnr)
 					continue
 				}