diffoscope.presenters.html: Invert logic as we use unconditional control flow.

                    footer = output_footer()

                    # we hit a limit, either max-report-size or single-page

                    if not make_new_subpage:

                        if not outputs:

                            # no more holes, don't traverse any more nodes

                            raise StopIteration

                        else:

                            # True = don't traverse this node's children, because they won't be output

                            # however there are holes in other pages, so don't break the loop just yet

                        if outputs:

                            # True = don't traverse this node's children,

                            # because they won't be output however there are

                            # holes in other pages, so don't break the loop

                            # just yet

                            return True

                        # No more holes, don't traverse any more nodes

                        raise StopIteration

                else:

                    # Unconditionally write the root node regardless of limits

                    assert node is root_difference