Fix flakey TestZKLeaderManager

On my little cluster, zk runs slow for whatever reason (TBD). This test always fails on me. Looking at it, there is at least a race given we stop mock masters and then put them on line again immediately... Testing if a thread Master is not going to give right answer always. Also, given zk runs slow on this host, just up the timeouts and number of Masters available. Sloppy but more likely to succeed (This test is for a deprecated class...)