Kicad API Change

[Michael-Bell]

Please see this issue from another KiCad plugin - xtoolbox/kicad_tools#19

This causes similar errors when running the kicadExportDxf.py script.

RoFI/util/kicadExportDxf.py

Line 36 in 2bec501

popt.SetExcludeEdgeLayer(True)