adding puppi fix for miniAOD definitions of charged particles

Hi, a small fix for PUPPI off of miniAOD
It should be std::abs but this would apply for all the code not just this addition. Better be consistent. Also a commented out code few lines below should be removed.  Etc. None of these came from this PR.
On the other hand the condition  if(fUseDZ && pDZ > -9999 && closestVtx == 0 && fabs(pReco.charge) > 0)
could be checked just once (and not twice as is now).  Similar few lines above. Maybe consider a separate PR for code optimization?