tst_QToolBar::accel() remove QApplicationPrivate::setActiveWindow()

2f6fe3a268 as made calls to
QApplicationPrivate::setActiveWindow() redundant.

Remove redundant calls.

Task-number: QTBUG-121488
Change-Id: Ic729e2675a6a51531b4ee055d2d0b84866331b28
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

tests/auto/widgets/widgets/qtoolbar/tst_qtoolbar.cpp

@@ -1022,7 +1022,6 @@ void tst_QToolBar::accel()
     QSignalSpy spy(action, SIGNAL(triggered(bool)));
 
     mw.show();
-    QApplicationPrivate::setActiveWindow(&mw);
     QVERIFY(QTest::qWaitForWindowActive(&mw));
 
     QTest::keyClick(&mw, Qt::Key_T, Qt::AltModifier);