minor fix in conf/py-failover.conf

Change-Id: I40ad416eacee6c658ba6428b1d88c217639f008d
Reviewed-on: http://review.couchbase.org/30165
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>