The commit referenced below claims to disable vertical
scrolling when idle tasks weren't being shown. However
it really addresses only a point in time when that 'i'
toggle is keyed. Left untouched were the up/down keys.

So this commit will simply finish the job of disabling
vertical scrolling whenever tasks which have used some
CPU are the only ones which are currently being shown.

Reference(s):
commit c07f6c5e



Signed-off-by: Jim Warner <james.warner@comcast.net>