Don't set PYTHONPATH if CONFIGURATION_TYPES.
Don't set PYTHONPATH if CONFIGURATION_TYPES.

Setting the PYTHONPATH doesn't help if the build puts the python
module in a config subdir, i.e. Debug or Release subdir.

hendradarwin/vtk-dicom,dgobbi/vtk-dicom,hendradarwin/vtk-dicom,dgobbi/vtk-dicom,hendradarwin/vtk-dicom,dgobbi/vtk-dicom