Don't delete labels when reordering of axes children (bug #63117) * graphics.in.h (children_property::do_set): Avoid using a temporary variable for new children list. Rephrase error message to be more accurate. Always return true for clarity.

%!test <*59661>
%! a = bug59661 (1);
%! b = bug59661 (1, 2);
%! assert (a == b, [true, false])