core : Rest API operations Fail on oVirt-engine's logs

Authentication layer logs error message when
Session-TTL header was not passed

Change-Id: I88b28fffff075e00a7903f33198040bc95ba3900
Bug-Url: https://bugzilla.redhat.com/1121391
Signed-off-by: Ravi Nori <rnori@redhat.com>
(cherry picked from commit db671feb5aa88164e153c1b9ff1555c73763a2f2)