ENH: Fix spelling error s/tropci/tropic/g
ENH: Fix spelling error s/tropci/tropic/g

The spelling error affected the variable name for library linkage
with ITK libraries in the module system.

InsightSoftwareConsortium/ITKAnisotropicDiffusionLBR,InsightSoftwareConsortium/ITKAnisotropicDiffusionLBR,InsightSoftwareConsortium/ITKAnisotropicDiffusionLBR