Revert "New upstream version 4.05.0."
It's been decided to allow the Fedora 27 Mass Rebuild to take place
before OCaml 4.05.0 is added to Fedora. To avoid this package
accidentally getting included in the mass rebuild, this commit reverts
the new upstream version, and then it will be un-re-verted after the
Mass Rebuild.
This reverts commit 40c060b8ecd3606034e5ba7fd782a6ed631fef18.