message: Removes unused variables.
  Attempts to fix root 6 compilation issue
diff: @@ -1694,8 +1694,6 @@ Int_t AliAnalysisTaskGammaHadron::CorrelatePi0AndTrack(AliParticleContainer* tra
  fClusEnergy->Fill(cluster->GetNonLinCorrEnergy(),Weight);
  Int_t iMCIndexClus1 = -1;
  - Int_t iMCRootPartClus1 = -1;
  - Int_t iMCTreeHeight1 = -1;
  if (fIsMC) {
  iMCIndexClus1 = FindMCPartForClus(cluster);
  }
  @@ -1924,9 +1922,6 @@ void AliAnalysisTaskGammaHadron::FillPi0CandsHist(AliTLorentzVector CaloClusterV
  AliAODMCParticle * mcPart1 = fMCParticles->GetMCParticle(mcIndex1);
  AliAODMCParticle * mcPart2 = fMCParticles->GetMCParticle(mcIndex2);
  - Int_t iMother1 = mcPart1->GetMother();
  - Int_t iMother2 = mcPart2->GetMother();
  -
  Int_t aMCTreeHeight1 = 0;
  Int_t aMCRootPartClus1 = FindMCRootPart(mcIndex1,&aMCTreeHeight1);
  Int_t aMCTreeHeight2 = 0;
  @@ -2592,7 +2587,7 @@ Int_t AliAnalysisTaskGammaHadron::FindMCLowComAnc(Int_t iMCIndex1, Int_t iMCInde
  Int_t iLastCommonAncestor = -1;
  - iMinHeight = min(lAncPart_1.size(),lAncPart_2.size());
  + iMinHeight = std::min(lAncPart_1.size(),lAncPart_2.size());
  for (Int_t i = 0; i < iMinHeight; i++) {
  if (lAncPart_1[iSize1-i] == lAncPart_2[iSize2-i]) {
  iLastCommonAncestor = lAncPart_1[iSize1-i];
  