Updating ITK version along 5.1 release for superbuild
Updating ITK version along 5.1 release for superbuild

Log of changes to ITK:
af780e8a03 BUG: Disable dynamic threading in noise filter.
449c571897 BUG: CUFFTW paths were not being set and unnecessary FFTW files used
d9e73e9a8b STYLE: apply clang-format
0b970d803d STYLE: make column limit more stringent in the examples
43a8972077 BUG: Add StatisticsImageFilter::SetNumberOfStreamDivisions Python
8c4d3da09d COMP: Add missing const qualifier
355c6cbda3 BUG: Double scaling introduced in refactoring

SimpleITK/SimpleITK,InsightSoftwareConsortium/SimpleITK,SimpleITK/SimpleITK,InsightSoftwareConsortium/SimpleITK,richardbeare/SimpleITK,InsightSoftwareConsortium/SimpleITK,richardbeare/SimpleITK,blowekamp/SimpleITK,richardbeare/SimpleITK,richardbeare/SimpleITK,SimpleITK/SimpleITK,richardbeare/SimpleITK,blowekamp/SimpleITK,richardbeare/SimpleITK,blowekamp/SimpleITK,blowekamp/SimpleITK,richardbeare/SimpleITK,InsightSoftwareConsortium/SimpleITK,SimpleITK/SimpleITK,blowekamp/SimpleITK,InsightSoftwareConsortium/SimpleITK,SimpleITK/SimpleITK,blowekamp/SimpleITK,InsightSoftwareConsortium/SimpleITK,SimpleITK/SimpleITK,blowekamp/SimpleITK,blowekamp/SimpleITK,SimpleITK/SimpleITK,InsightSoftwareConsortium/SimpleITK,richardbeare/SimpleITK,SimpleITK/SimpleITK,InsightSoftwareConsortium/SimpleITK