Include sage fixes from ecls-1.patch into maxima 5.32.1 ebuild.

This redoes the maxima build fixes for the latest version of maxima. It would be really nice if we could get this addressed in the main portage tree, instead of having to fix every single version of maxima again and again. So I just filed [bug 499634](https://bugs.gentoo.org/show_bug.cgi?id=499634) to track this request.

Until then, though, please include this fix. And consider adding `::sage-on-gentoo` to the dependencies on maxima. I didn't do so because I don't see this approach anywhere else in the overlay, and I don't see permission to use this syntax in the PMS docs, but I did see it described in the portage docs, so I guess it should work.