bug #3665 [Cookbook][Test] fix sample code (inalgnu)

This PR was merged into the 2.3 branch.

Discussion
----------

[Cookbook][Test] fix sample code

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all

Commits
-------

370d614 [Cookbook][Test]fix sample code

cookbook/testing/profiling.rst

@@ -51,7 +51,7 @@ finish. It's easy to achieve if you embed the token in the error message::
 
     $this->assertLessThan(
         30,
-        $profile->get('db')->getQueryCount(),
+        $profile->getCollector('db')->getQueryCount(),
         sprintf(
             'Checks that query count is less than 30 (token %s)',
             $profile->getToken()