Fixed timing issue retrieving aggregator descriptor.
Fixed timing issue retrieving aggregator descriptor.

kairosdb/kairosdb,ppbizapps/kairosdb,ppbizapps/kairosdb,kairosdb/kairosdb,kairosdb/kairosdb,ppbizapps/kairosdb,ppbizapps/kairosdb,kairosdb/kairosdb,ppbizapps/kairosdb,kairosdb/kairosdb,kairosdb/kairosdb