COMP: Update VTK to include tweak to vtkImageHistogramStatistics

$ git shortlog 4e0ca685..c88dfed
Andinet Enquobahrie (2):
      ENH: Add NumberOfVoxels statistics measure
      ENH: Add mode statistical measure

Co-authored-by: Andinet Enquobahrie <andinet.enqu@kitware.com>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22933 3bd1e089-480b-0410-8dfb-8563597acbee