Update mc.MGPy8EG_Wtaunu_FxFx_3jets.py for leptonic decays ONLY
I added the following lines to the Wtaunu FxFx JOs to allow taus to decay only to leptons:
#tau decay to electron or muons ONLY
genSeq.Pythia8.Commands += [
"15:onMode = off",
"15:onIfAny = 11 13"
]