The test introduced in bb86141 turns out to be flaky in CI[1] with the
following error message:
[03:40:43.047] stderr:
[03:40:43.047] # Failed test 'connect : matches'
[03:40:43.047] # at
/tmp/cirrus-ci-build/src/test/postmaster/t/003_start_stop.pl line 78.
[03:40:43.047] # 'psql: error: connection to server on socket
"/tmp/X7O4HUuFUZ/.s.PGSQL.25995" failed: FATAL: role "invalid_user"
does not exist'
[03:40:43.047] # doesn't match '(?^:FATAL: sorry, too many clients already)'
[03:40:43.047] # Looks like you failed 1 test of 25.
[03:40:43.047]
[03:40:43.047] (test program exited with status code 1)
[1]: https://cirrus-ci.com/task/5571017969500160?logs=test_world#L256
