Fix limits in enflux set_par

The upper energy limit when setting the enflux parameter (e.g.,
set_par("enflux(1).E_min",hard[0],1,0,10)) was set to 10keV. This
resulted in error when evaluating the model in an energy range larger
than this (e.g., hard_band=[8,20]).
--> Increase energy limit to 100keV