Update FFTConvolution baseline for change in origin

The ITK filter has been updated to correctly respect the output
origin.

Change-Id: I5b4b1a96223cec5669b9b5c253185d456ddde42f
Merge topic 'SIMPLEITK-543_UpgradeITKTowards4.6' into next

2e3b9e7f Update FFTConvolution baseline for change in origin