GRHD: remove stale isadmissible check from cons2prim
It sems that atm we can get away with slightly negative tau values. Furthermore, I think the logic for correcting tau wasn't really sound, and I could not retrace anymore how I obtained that fix.
It sems that atm we can get away with slightly negative tau values. Furthermore, I think the logic for correcting tau wasn't really sound, and I could not retrace anymore how I obtained that fix.