message: Fix division by zero crash in AliDielectronVarManager::FillAODTrack()
diff: @@ -1137,7 +1137,7 @@ inline void AliDielectronVarManager::FillVarAODTrack(const AliAODTrack *particle
  // Reset AliESDtrack interface specific information
  if(Req(kNclsITS)) values[AliDielectronVarManager::kNclsITS] = particle->GetITSNcls();
  - if(Req(kITSchi2Cl)) values[AliDielectronVarManager::kITSchi2Cl] = particle->GetITSchi2() / particle->GetITSNcls();
  + if(Req(kITSchi2Cl)) values[AliDielectronVarManager::kITSchi2Cl] = (particle->GetITSNcls()>0)? particle->GetITSchi2() / particle->GetITSNcls() : 0;
  if(Req(kNclsTPC)) values[AliDielectronVarManager::kNclsTPC] = tpcNcls;
  if(Req(kNclsSTPC)) values[AliDielectronVarManager::kNclsSTPC] = tpcNclsS;
  if(Req(kNclsSFracTPC)) values[AliDielectronVarManager::kNclsSFracTPC] = tpcNcls>0?tpcNclsS/tpcNcls:0;
  