BB10: Do not send deactivate event twice

On BB10, NAVIGATOR_WINDOW_INACTIVE is called before
NAVIGATOR_WINDOW_INVISIBLE, already triggering handleWindowGroupDeactivated()

Change-Id: I7d82c0220fe8dc8e87bfa2b31af6085c7d1d6cee
Reviewed-by: Kevin Krammer <kevin.krammer@kdab.com>
Reviewed-by: Bernd Weimer <bweimer@blackberry.com>
Reviewed-by: Nicolas Arnaud-Cormos <nicolas@kdab.com>

src/plugins/platforms/qnx/qqnxbpseventfilter.cpp

@@ -226,7 +226,9 @@ bool QQnxBpsEventFilter::handleNavigatorEvent(bps_event_t *event)
 #endif
             break;
         case NAVIGATOR_WINDOW_INVISIBLE:
+#if defined(Q_OS_BLACKBERRY_TABLET)
             m_navigatorEventHandler->handleWindowGroupDeactivated(id);
+#endif
             break;
         }