Moving ITK superbuild version along ITK v4.5.0 release branch

Change-Id: Ib247660cc1604f37a2aa11a43e57a4cfe350ed0e
Merge topic 'SIMPLEITK-467_UpdateITKSuperbuildTowards4.5.1' into next

9b75a955 Moving ITK superbuild version along ITK v4.5.0 release branch