Importing mod preset fails during Icon import due to wrong 'shift' table format

[IcedLance]

------------- Error -------------
Failed to load mod "foremanexport": __foremanexport__/instrument-after-data.lua:54: attempt to concatenate field '?' (a nil value)
stack traceback:
	__foremanexport__/instrument-after-data.lua:49: in function 'ExportIcon'
	__foremanexport__/instrument-after-data.lua:98: in main chunk
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apparently 'shift' can also have named 'x','y' fields instead of numeric ones, much like 'tint', which is already accounted for.