Default "no" splitting in multi_geometry when using grazing incidence units

[EdgarGF93]

We did it for standard ai.integrate2d, but not in multi_geometry which is using ("full", "histogram", "cython") by default So, by default, GI + multi_geometry will fill the missing wedge

[EdgarGF93]

Actually, it's only in the integrate1d_fiber , it's not using it through the integrate2d either ... :)

[kif]

There are warning in place ...