autoscaling fix LoadBalancer reload static resolve

Since https://review.openstack.org/#/c/31083/ we're using the
Resource.update() method to update the LoadBalancer, which requires
the resource snippet to be statically resolved (as is done in
parser.Stack for stack updates)

Fixes bug #1191705

Change-Id: Id2017a912472ddb48245682c5b6392cbcb9e4c60