message: Do not add sparse for bkg if not used
diff: @@ -1639,6 +1639,10 @@ void AliAnalysisTaskSEDs::CreateCutVarsAndEffSparses()
  if (fReadMC)
  {
  TString label[3] = {"fromC", "fromB", "bkg"};
  + Int_t nSparseReco = 2;
  + if(fFillBkgSparse)
  + nSparseReco = 3;
  +
  for (Int_t iHist = 0; iHist < 2; iHist++)
  {
  TString titleSparse = Form("MC nSparse (%s)- %s", fFillAcceptanceLevel ? "Acc.Step" : "Gen.Acc.Step", label[iHist].Data());
  @@ -1657,7 +1661,7 @@ void AliAnalysisTaskSEDs::CreateCutVarsAndEffSparses()
  fOutput->Add(fnSparseMCDplus[iHist]);
  }
  }
  - for (Int_t iHist = 2; iHist < 5; iHist++)
  + for (Int_t iHist = 2; iHist < nSparseReco + 2; iHist++)
  {
  fnSparseMC[iHist] = new THnSparseF(Form("fnSparseReco_%s", label[iHist - 2].Data()), Form("MC nSparse (Reco Step)- %s", label[iHist - 2].Data()), nSparseAxes, nBinsReco, xminReco, xmaxReco);
  for (Int_t iAxis = 0; iAxis < nSparseAxes; iAxis++)
  