Fix getTerrainContactPoints in RBSphere
Fix getTerrainContactPoints in RBSphere

Return an empty array for non-zero radius spheres.

hanssusilo/drake,manuelli/drake,crogers3/drake,scottviteri/drake,sheim/drake,billhoffman/drake,astrorog/drake,tkoolen/drake,scottviteri/drake,thientu/drake,manuelli/drake,thientu/drake,billhoffman/drake,billhoffman/drake,sheim/drake,crogers3/drake,psiorx/drake,edowson/drake,crogers3/drake,psiorx/drake,hanssusilo/drake,hanssusilo/drake,psiorx/drake,tkoolen/drake,tkoolen/drake,scottviteri/drake,manuelli/drake,astrorog/drake,hanssusilo/drake,sheim/drake,astrorog/drake,manuelli/drake,edowson/drake,thientu/drake,sheim/drake,scottviteri/drake,hanssusilo/drake,psiorx/drake,manuelli/drake,psiorx/drake,thientu/drake,psiorx/drake,crogers3/drake,billhoffman/drake,edowson/drake,astrorog/drake,scottviteri/drake,hanssusilo/drake,edowson/drake,edowson/drake,astrorog/drake,tkoolen/drake,billhoffman/drake,scottviteri/drake,edowson/drake,thientu/drake,scottviteri/drake,sheim/drake,crogers3/drake,crogers3/drake,tkoolen/drake,billhoffman/drake,edowson/drake,crogers3/drake,sheim/drake,crogers3/drake,astrorog/drake,psiorx/drake,manuelli/drake,hanssusilo/drake,billhoffman/drake,tkoolen/drake,sheim/drake,thientu/drake,thientu/drake,hanssusilo/drake,psiorx/drake,edowson/drake,billhoffman/drake,astrorog/drake,sheim/drake,manuelli/drake,tkoolen/drake