add workaround for wrong pillar lookup in elasticsearch-formula
elasticsearch-formula expects elasticsearch:lookup:use_repo instead of
the documented elasticsearch:use_repo, see
see https://github.com/saltstack-formulas/elasticsearch-formula/pull/48
Add the "wrong" version to ensure everything works as expected (and keep
the "right" one to be sure we don't break anything when the fix gets
accepted in the formula ;-)