Add override

Change-Id: Iafa8e21d7d47797c1c085aced9a0cd92179385a2
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

src/network/kernel/qhostinfo_p.h

@@ -108,7 +108,7 @@ public Q_SLOTS:
     }
 
 protected:
-    bool event(QEvent *event)
+    bool event(QEvent *event) override
     {
         if (event->type() == QEvent::MetaCall) {
             auto metaCallEvent = static_cast<QMetaCallEvent *>(event);