Inconclusive tests treated as failures at build server

Some tests can return as inconclusive, e.g. SSL wasn't enabled at the
backend so the test effectively couldn't be run.

We don't want to bother developers who haven't set up Postgresql to
support everything - so inconclusive is very similar to ignore. However,
on the build server we want inconclusive tests to show up as failures,
otherwise we may miss regressions because of misconfiguration.