The wait condition used for integ tests by default calls the cluster
health api with wait_for_nodes nd wait_for_status. However, xpack
overrides the wait condition to add auth, but most of these conditions
still looked at the root ES url, which means the tests are susceptible
to race conditions with the check and node startup. This change modifies
the url for the authenticated wait condtion to check the health api,
with the appropriate wait_for_nodes and wait_for_status.
Original commit: elastic/x-pack-elasticsearch@0b23ef528f