message: add check to avoid seg fault
diff: @@ -262,9 +262,8 @@ void AliAnalysisTaskBaseWeights::AnaEventMC() {
  fNaccWeightedSys = 0;
  fNaccWeightedSysRandom = 0;
  - fMCSpectraWeights = static_cast<AliMCSpectraWeightsHandler*>(
  - fEvent->FindListObject("fMCSpectraWeights"))
  - ->fMCSpectraWeight;
  + AliMCSpectraWeightsHandler* mcWeightsHandler = static_cast<AliMCSpectraWeightsHandler*>(fEvent->FindListObject("fMCSpectraWeights"));
  + fMCSpectraWeights = (mcWeightsHandler) ? mcWeightsHandler->fMCSpectraWeight : nullptr;
  if (fMCSpectraWeights) {
  DebugPCC("found fMCSpectraWeights in this event\n");
  