tst_QLineEdite::task174640_editingFinished() remove setActiveWindow()

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

Remove redundant calls.

Task-number: QTBUG-121488
Change-Id: I5a3a154bf64fceaed8df0bb3a70c2359e7fd2fb2
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

tests/auto/widgets/widgets/qlineedit/tst_qlineedit.cpp

@@ -3722,7 +3722,6 @@ void tst_QLineEdit::task174640_editingFinished()
     layout->addWidget(le2);
 
     mw.show();
-    QApplicationPrivate::setActiveWindow(&mw);
     mw.activateWindow();
     QVERIFY(QTest::qWaitForWindowActive(&mw));
     QCOMPARE(&mw, QApplication::activeWindow());