Select first node as bootstrap node not using name
Select first node as bootstrap node not using name

This fixes a regression which reintroduced bug #1640449 because
we hard-code the node index/name instead of sorting the map of servers

Change-Id: Iaffc66a41edf176dde3b5adf603a9cff6db7aa24
Closes-Bug: #1724888

dprince/tripleo-heat-templates,openstack/tripleo-heat-templates,openstack/tripleo-heat-templates,dprince/tripleo-heat-templates