Improve compatibility after wxTopLevelWindow::Layout() change

The changes of 3241e7a850 resulted in
Layout() not called any longer from wxEVT_SIZE handler for windows that
didn't use neither sizers nor constraints themselves, but did call
SetAutoLayout(true).

Fix this regression by checking for GetAutoLayout() explicitly.

See #18472.

src/common/toplvcmn.cpp

@@ -422,7 +422,8 @@ bool wxTopLevelWindowBase::Layout()
 
 
     // if we're using sizers or constraints - do use them
-    if ( GetSizer()
+    if ( GetAutoLayout()
+            || GetSizer()
 #if wxUSE_CONSTRAINTS
                     || GetConstraints()
 #endif