Related: fdo#80633 dialog size cache has to be invalidated too

otherwise the VclExpander will have no effect

Change-Id: I039fa361d7088dfe4a6ff849623e34b27e2be26b

vcl/source/window/dialog.cxx

@@ -1238,6 +1238,9 @@ void Dialog::queue_resize()
         return;
     if (!isLayoutEnabled())
         return;
+    WindowImpl *pWindowImpl = mpWindowImpl->mpBorderWindow ? mpWindowImpl->mpBorderWindow->mpWindowImpl : mpWindowImpl;
+    pWindowImpl->mnOptimalWidthCache = -1;
+    pWindowImpl->mnOptimalHeightCache = -1;
     maLayoutTimer.Start();
 }