vdsm: packaging: always restart libvirtd

required if vdsm does not restart when asked to configure libvirtd.

Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1043524
Change-Id: I9be578c00823f50e2eee446f0661aed624d0d909
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>