CBQE-0:fix concurrent tuq queries with failover

Change-Id: Ic782adf8c05b9ce68aed11c42e5f67ea522c60c1
Reviewed-on: http://review.couchbase.org/30091
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>