CBQE-1137: add debug info for connections test

Change-Id: I6abf8ecc6567ed65949167cab22a2245d5dec004
Reviewed-on: http://review.couchbase.org/25225
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>