- fixed compilation of POSIX Debug targets

src/rendering/2d/f_wipe.cpp:291: undefined reference to `Wiper_Melt::HEIGHT'

src/rendering/2d/f_wipe.cpp

@@ -160,7 +160,7 @@ class Wiper_Melt : public Wiper
 	bool Run(int ticks) override;
 
 private:
-	static const int WIDTH = 320, HEIGHT = 200;
+	static constexpr int WIDTH = 320, HEIGHT = 200;
 	int y[WIDTH];
 };