Ubuntu: Sync with vdsm.spec.in

Recently we split zombiereaper and made some changes in libvirt
configuring. This patch update Ubuntu packaging scripts to keep up with
vdsm.spec.in.

Change-Id: Ib4eccbc0a32847036a2b4de8510ed352ddc124bd
Signed-off-by: Zhou Zheng Sheng <zhshzhou@linux.vnet.ibm.com>
Reviewed-on: http://gerrit.ovirt.org/21297
Reviewed-by: Dan Kenigsberg <danken@redhat.com>