CBQE-2317 add sleep time after restart
couchbase server so that cb server startup comopletely

Change-Id: Id67126af7e203e1eb51fd8377f5afbea654a1fc7
Reviewed-on: http://review.couchbase.org/39213
Reviewed-by: Thuan Nguyen <soccon@gmail.com>
Tested-by: Thuan Nguyen <soccon@gmail.com>