message: protection for missing userinfo
diff: @@ -199,10 +199,12 @@ void AliAnalysisTaskNanoAODFilter::FinishTaskOutput() {
  AliAODExtension *extNanoAOD = handler->GetFilteredAOD("AliAOD.NanoAOD.root");
  // copy production version info
  + if (inputHandler->GetUserInfo()) {
  AliVEventHandler* inputHandler = AliAnalysisManager::GetAnalysisManager()->GetInputEventHandler();
  TObject* prodInfo = inputHandler->GetUserInfo()->FindObject("alirootVersion");
  if (prodInfo)
  extNanoAOD->GetTree()->GetUserInfo()->Add(prodInfo->Clone());
  + }
  Printf("****************************************************************");
  extNanoAOD->GetTree()->GetUserInfo()->Add(AliNanoAODTrackMapping::GetInstance(fReplicator->GetVarListTrack()));
  