make simple-test fails

Steps to reproduce:

1. Checkout the Couchbase with the master manifest
2. Go to the testrunner directory
3. run "make simple-test"

That commit broke it:
https://github.com/couchbase/testrunner/commit/2a7dd34cc8961f207934294cdfa734c4bd0c09f0

The reason is that it hard-codes port 8091, but the ./cluster_run script from ns_server runs the nodes on port 9000 (and higher).

Reverting that commit makes all the tests from "make simple-test" pass again.