Fix missing labels in queryTests.php table (#2202)

#1455 mistakenly used the test ID instead of the test output ID to find
labels for the queryTests page. This issue was separately resolved in
the 3.5 release series by the refactor in #2148.

Failures like this are a good motivation for our effort to move to a
GraphQL API. With GraphQL, there is a single source of truth about where
labels come from, and there isn't a need to separately query the labels
in dozens of different locations. These types of failures are also a
good motivation for more complete testing data, with most tables having
at least thousands of rows. With limited data, this failure went
unnoticed because each test ID corresponds to a test output ID in the
testing environment. This limited issue was resolved by the removal of
the test table in #2148.

app/cdash/app/Controller/Api/QueryTests.php

@@ -367,7 +367,7 @@ public function getResponse()
  label2test
  WHERE
  label.id=label2test.labelid
- AND label2test.outputid=test.id
+ AND label2test.outputid=build2test.outputid
  AND label2test.buildid=b.id
  ) AS labelstring
  $output_select