core: Fix failed unit test for http://gerrit.ovirt.org/#/c/26068

Patch http://gerrit.ovirt.org/#/c/26068 caused a failed dao unit test
This patch fixes it.

Change-Id: I741dbca28732fc27bd90c9598a040f4a969e9cb0
Signed-off-by: lzelkha@redhat.com <lzelkha@redhat.com>