fixing theory db entries from 118 to 123
Created by: scarrazza
This is related to the nf=3,4 bug in 3.1.
The theory.db for theories 118-123 have the wrong Qref (always MZ) and respective alphas(Qref). The Qref should be identical the last quark mass (nf) -eps, and alphas(Qref) computed by back-evolving from MZ.