CBQE-0: xdcr.biXdcr.bidirectional.load_with_failover_then_add_back increase timeout value in conf file

Change-Id: I231ed5047dd4cc1db44d98efc3c0a29831c760a8
Reviewed-on: http://review.couchbase.org/31382
Reviewed-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>
Tested-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>