fixes #3855 - pin ruby-libvirt to 0.4 for Ruby 1.8 workaround

(cherry picked from commit c6d5131967fdb5ada9956fb9e83079db10ab1c29)
fixes #3661 - mis-redirection from /hosts/fqdn/edit to /hosts

(cherry picked from commit 625e5c7bef437a25c874195e1e1f938ff9ab5e2c)