Bug#925540: qhull: add libqhullcpp to installed libraries

[Barak A. Pearlmutter]

Had not noticed that, thanks!

Next time, do feel free to 0-day NMU, pushing to the shared repo.

But, now that I've seen it, looks great. I'm going to just upload to
unstable. (Hence the term, right?)

Cheers,

--Barak.