include Rivet_i back in the build
in LCGpython3_atlas_1 Rivet was removed from the build (with a comment that it should be put back for the next LCG layer) This MR is to put Rivet_i back in the AthGeneration build
CC @cgutscho
in LCGpython3_atlas_1 Rivet was removed from the build (with a comment that it should be put back for the next LCG layer) This MR is to put Rivet_i back in the AthGeneration build
CC @cgutscho