Fixes by clang-tidy

ApplicationLibCode/UserInterface/RiuMainWindowBase.h

@@ -48,7 +48,7 @@ class RiuMainWindowBase : public QMainWindow
 
 public:
 	RiuMainWindowBase();
-	~RiuMainWindowBase();
+	~RiuMainWindowBase() override;
 
     virtual QString mainWindowName() = 0;
 

ApplicationLibCode/UserInterface/RiuMdiArea.h

@@ -30,7 +30,7 @@ class RiuMdiArea : public QMdiArea
 
 public:
     RiuMdiArea( QWidget* parent = nullptr );
-    ~RiuMdiArea();
+    ~RiuMdiArea() override;
 
     std::list<QMdiSubWindow*> subWindowListSortedByPosition();