Re-enable grafana gpgcheck
Re-enable grafana gpgcheck

grafana package is signed now.

Change-Id: I5e0cfe138198b37328c7a7f56413f48999118cfa
Closes-Bug: #1664272

coolsvap/kolla,mrangana/kolla,coolsvap/kolla,nihilifer/kolla,GalenMa/kolla,nihilifer/kolla,stackforge/kolla,intel-onp/kolla,intel-onp/kolla,stackforge/kolla,openstack/kolla,stackforge/kolla,GalenMa/kolla,coolsvap/kolla,rahulunair/kolla,openstack/kolla,mrangana/kolla,rahulunair/kolla