Missing newline between TODOs and the next section when not grouping

## Problem description

When items are not grouped, there is no empty line between the last item of the TODOs section and the next section, see screen shot:

Note: when items are grouped, there is an empty line.

## What should be changed

As magit always has an empty line after an unfolded section, this should also be the case if the TODOs are not grouped.