* bug #16748 fixed: Scilab can use ocaml 4.11 or later without unsafe strings

This change will enforce a "recent" version of OCaml. The unsafe-string usage was a temporary measure to have an update window for the CC OCaml upgrade and this should be ok now.

see http://bugzilla.scilab.org/show_bug.cgi?id=16748 and search ocaml on https://salsa.debian.org/science-team/scilab/-/tree/master/debian/patches for comments.