Fix warning in qml testcase

'root.done' doesn't exist. There is a timer that flips 'when' explicitly
when the testcase is ready to run.

Change-Id: I8d9b1b36c1e605db43a4c86b5694956c864896a4
Reviewed-by: J-P Nurmi <jpnurmi@qt.io>

tests/auto/qmltest-blacklist/animators/tst_stopped.qml

@@ -37,7 +37,7 @@ Item {
     TestCase {
         id: testcase
         name: "animators-stopped"
-        when: root.done
+        when: false
         function test_endresult() {
             verify(true);
         }