top: turn off the 'Ctrl' bottom window with 1 more key

top: turn off the 'Ctrl' bottom window with 1 more key

In that commit shown below, the concept of a corrupted
display was introduced so that 'Ctrl' windows could be
redrawn now that they were made more persistent. Well,
it turns out there is another case where redrawing was
necessary. That is when transitioning between task and
thread modes. So this patch addresses those occasions.

Reference(s):
. May, 2022 - introduced Frames_signal BREAK_screen
commit d66c1f39b52d53ec279fc638aa4a6352d7672201

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