message: Implemented second Francesco's suggestion
diff: @@ -232,7 +232,7 @@ void AliAnalysisTaskCheckEvSel::UserCreateOutputObjects()
  PostData(1,fOutput);
  - if(fHistZVertexSPDBadTrackVert) {
  + if(fEnableVertexNtuple) {
  OpenFile(3); // 3 is the slot number of the ntuple
  fNtupleZvtxDistVsWhyRej = new TNtuple("fNtupleZvtxDistVsWhyRej","fNtupleZvtxDistVsWhyRej","zSPDvertex:zTRKvertex:NcontributorszSPD:NcontributorszTRK:whyrejection:vtxtype");
  