Updated openstack/openstack
Project: openstack-dev/devstack  5ee1cd3b472d29578537d992c50da700a449508a
null
update heat image to the 64bit one we cached previously

start caching the next 64bit update image to deal with heat
breaks we see from time to time.

Change-Id: If62840f4807151ada1598046fb7ad47c7210df12