Fix mistake of calculating wrong size

Sine Striker

2023-12-07 f452b4a64bbef0d84518499a663dc527527d11b9

 src/core/contexts/win32windowcontext_p.h

@@ -37,6 +37,9 @@
        bool customWindowHandler(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam,
                                 LRESULT *result);

        static bool nonClientCalcSizeHandler(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam,
                                             LRESULT *result);

    protected:
        WId windowId = 0;