Add Geant4 to lhcb-gaudy-head-py3
When I have added Gauss to lhcb-gaudi-head-py3 slot I completely forgot that we need also Geant4, which is done here.
When I have added Gauss to lhcb-gaudi-head-py3 slot I completely forgot that we need also Geant4, which is done here.