Fix catz test error

Fix catz test error

The catz system test included a test case that was looking for a single
answer record after an update, when it should have been looking for two.
The test usually passed because of timing - the first dig usually got a
response before the update was completed - but occasionally the update
processed fast enough for the test to fail. On investigation, it turned
out to be the test that was wrong.

(cherry picked from commit 9b6060c6c476998c9e5f8faf6169ab148dd9a103)