Revert "Skip unstable test"

This reverts commit 8e0c5b59f5.

This test doesn't fail any more.

Task-number: QTBUG-23976
Change-Id: I77704e7811c4c335cb5836ba7645a8804c13e12d
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>

tests/auto/quick/qquickmousearea/tst_qquickmousearea.cpp

@@ -933,7 +933,6 @@ void tst_QQuickMouseArea::preventStealing()
 
 void tst_QQuickMouseArea::clickThrough()
 {
-    QSKIP("QTBUG-23976 Unstable");
     //With no handlers defined click, doubleClick and PressAndHold should propagate to those with handlers
     QScopedPointer<QQuickView> window(new QQuickView);
     QByteArray errorMessage;