systemd init: no need to stop conflicting services

We use the explict systemd Conflicts= statement for that.

This patch is sent only to the ovirt-3.3 branch, as in master branch we
already have an independent systemd service management.

Bug-Url: https://bugzilla.redhat.com/999664
Change-Id: I7b5469ce61ae8aca353c2c7345a8a719ab0e898f
Signed-off-by: Dan Kenigsberg <danken@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/19046
Reviewed-by: Zhou Zheng Sheng <zhshzhou@linux.vnet.ibm.com>
Reviewed-by: Yaniv Bronhaim <ybronhei@redhat.com>