Fix charge of EFTracking smeared tracks
In the previous implementation, we had
double pt = std::sin(theta)/(trk->qOverP());
...
double qoverPt = trk->charge()*1000./pt; //this must be in GeV
mySmearer->AddTrack(trk->d0(),trk->z0(),qoverPt,trk->eta(),trk->phi0());
So q/pT was always positive and the smeared tracks got only positive q/p. This MR fixes this issue.