grenade: do not use the removed glance v1 API
grenade: do not use the removed glance v1 API

glance v1 API has been disabled by default in DevStack before Pike:
https://review.openstack.org/#/c/343129/

Change-Id: Ia76ca3422673eec251b5c6076cf26056e0008a69

openstack/sahara,openstack/sahara