Avoid 'jumps' in faces panel

There have been some complains about 'jumps' in the faces view. This merge request disables 'jumps' ("scrollTo" function) in the "Thumbnails" view in the "People" section.

This should resolve reported 'bugs 'jumps' when confirming/rejecting faces (436726, 444692 and related).

I think it should also avoid 'jumps' during face detection/recognition (402322 and related), but I am not sure as all these different scenarios are difficult to test/debug.