use `set literal` to replace `set` which is twice faster than `set`
use `set literal` to replace `set` which is twice faster than `set`

Change-Id: Id30381755e22a061c8daca73eb78b0e04a767075

BiznetGIO/horizon,NeCTAR-RC/horizon,NeCTAR-RC/horizon,NeCTAR-RC/horizon,BiznetGIO/horizon,yeming233/horizon,ChameleonCloud/horizon,noironetworks/horizon,BiznetGIO/horizon,ChameleonCloud/horizon,yeming233/horizon,yeming233/horizon,openstack/horizon,openstack/horizon,ChameleonCloud/horizon,openstack/horizon,noironetworks/horizon,NeCTAR-RC/horizon,noironetworks/horizon,BiznetGIO/horizon,openstack/horizon,noironetworks/horizon,ChameleonCloud/horizon,yeming233/horizon