Treat wxToolbook symmetrically with others in the notebook sample.

Use wxToolbook as the default notebook type if the other ones are not
available.

Closes #12610.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65895 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/notebook/notebook.cpp

@@ -291,6 +291,8 @@ MyFrame::MyFrame()
     m_type = Type_Listbook;
 #elif wxUSE_TREEBOOK
     m_type = Type_Treebook;
+#elif wxUSE_TOOLBOOK
+    m_type = Type_Toolbook;
 #else
     #error "Don't use Notebook sample without any book enabled in wxWidgets build!"
 #endif