MB-7168:30 seconds is not enough between failover and rebalance

Change-Id: I9a7ecfeb9f54120d4f886d2cedec6453c957a0cf
Reviewed-on: http://review.couchbase.org/25587
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>