fixes #3855 - pin ruby-libvirt to 0.4 for Ruby 1.8 workaround
(cherry picked from commit c6d5131967fdb5ada9956fb9e83079db10ab1c29)
fixes #3855 - pin ruby-libvirt to 0.4 for Ruby 1.8 workaround
(cherry picked from commit c6d5131967fdb5ada9956fb9e83079db10ab1c29)