Remove broken links for Oneiric

I got errors over multiple days.

For oneiric32:

    [vagrant] Downloading with Vagrant::Downloaders::HTTP...
    [vagrant] Downloading box: http://vagrant.cedric-ziel.com/oneiric32.box
    Bad status code: 404

For oneiric64:

    [vagrant] Downloading with Vagrant::Downloaders::HTTP...
    An error occurred while trying to download the specified box. This most
    often happens if there is no internet connection or the address is
    invalid.