qt: avoid both virtual and override on dtors

When inheriting from classes with a virtual destructor, it is not needed to declare the destructor both as virtual and override. In line with the normal policy for virtual vs override, use virtual only when declaring the base class destructor.

modules/gui/qt/network/networkmediamodel.hpp

@@ -147,7 +147,7 @@ public:
     Q_PROPERTY(int count READ getCount NOTIFY countChanged)
 
     explicit NetworkMediaModel(QObject* parent = nullptr);
-    virtual ~NetworkMediaModel() override;
+    ~NetworkMediaModel() override;
 
     QVariant data(const QModelIndex& index, int role) const override;
     QHash<int, QByteArray> roleNames() const override;