message: Fix EMCAL cell multiplicity calculation
  Usage of operator!= for finding the cell ID in set prevented
  any cell from being selected.
diff: @@ -391,7 +391,7 @@ int AliAnalysisTaskEmcalClustersRef::GetEMCALCellOccupancy(double ecut){
  for(short icell = 0; icell < emccells->GetNumberOfCells(); icell++){
  if(emccells->GetAmplitude(icell) > ecut){
  int cellID = emccells->GetCellNumber(icell);
  - if(cellIDs.find(cellID) != cellIDs.end()) cellIDs.insert(cellID);
  + if(cellIDs.find(cellID) == cellIDs.end()) cellIDs.insert(cellID);
  }
  }
  return cellIDs.size();
  