deploy: add rpcbind to the needed services

Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=977940
Change-Id: I5ff0b85d5a7c439fbd8d6946f0861c5f27d0042e
Signed-off-by: Federico Simoncelli <fsimonce@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/16741
Reviewed-by: Allon Mureinik <amureini@redhat.com>
Reviewed-by: Ayal Baron <abaron@redhat.com>