CloudBees Replication Parent 2485

As of 2.414.3.7 and then aggravated in 2.492.1.3, startup of an HA controller containing some jobs with many historical (completed) builds could be relatively slow, particularly if other running replicas were under heavy CPU load. An optimization was made to the HA-specific aspect of loading the list of build numbers from disk to reduce the overhead, speeding up rolling restarts.