14445: Fix vtkImageStencilData IsInside upper bound.

The upper bound check on the IsInside method was off by one.

Change-Id: If19f632d5490018cbeda0d8399153512b37b1891
Merge topic '14445_stencil_isinside' into master

c68bd98d 14445: Fix vtkImageStencilData IsInside upper bound.