ENH: Bump ExternalData.cmake.
ENH: Bump ExternalData.cmake.

Use the latest version in ITK to avoid conflicts.

Change-Id: I6f2d1a35540a76d8e5836c61916da2a182fe3516

InsightSoftwareConsortium/ITKExamples,InsightSoftwareConsortium/ITKExamples,InsightSoftwareConsortium/ITKExamples,InsightSoftwareConsortium/ITKExamples,InsightSoftwareConsortium/ITKExamples