Do not draw rectangles with the same left and right boundaries

These should not be drawn at all, but the expansion logic for OVERSHOOT
and LEFT and RIGHT rectangles will expand the rectangle into something
that gets drawn.

Test: manual - triggered smart selection and verified that rectangles on
non-primary lines do not get prematurely shown

Change-Id: I5235e4b214401e6ceee3f07bc5cc937907c261ba