bug: shapefile_utils export fail with disu export

[laat0003]

Hi,

shapefile_utils export fails with disu export when angledegx.array is None

If angledegx.array is None then function model_attributes_to_shapefile() will fail in the attribute grab loop when it tests for the array shape.

This is presently line 307 in the shapefile_utils.py file develop branch online.
It is line 284 in the same file used in the release version 3.3.6

I got it working with the following starting at line 305 in dev branch online (same as line 281 in release 3.3.6)

if (
a.data_type == DataType.array2d # original code
and a.array is not None # I added this
and a.array.shape == horz_shape # original code
):

Hope that helps,
Tariq