Fix the automatic calculation of vertical profiles

When T and rh are only given as (1x2) array, i.e., bottom and top value of the profile, a linear profile was taken to calculate the isotope profiles. The calculation was only correct, if profiles of T and rh were used as input. This behavior doesn't make much sense, as it would require to pre-calculate the profiles with a Rayleigh ascent.

With this fix, profiles of T and rh are directly calculated with the rayleigh ascent. A linear profile for these variables is only calculated if namelist.profilecalc = 0