message: Update PWGUDupcLinkDef.h
  I mistakenly removed this line. Adding it back. Sorry
diff: #pragma link C++ class Polarization+;
  #pragma link C++ class AliAnalysisTaskSatellites+;
  #pragma link C++ class AliAnalysisTaskUpcFourPi+;
  -
  +#pragma link C++ class AliAnalysisTaskUpc4Pi+;
  #endif
  