avoid GTK3 warning "GtkNotebook %p is mapped but visible child wxPizza %p is not mapped"

whatever problem this hack was supposed to solve, this was not the way to fix it

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@69522 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/notebook.cpp

@@ -352,8 +352,6 @@ wxNotebookPage *wxNotebook::DoRemovePage( size_t page )
     if ( !client )
         return NULL;
 
-    gtk_widget_unrealize( client->m_widget );
-
     // we don't need to unparent the client->m_widget; GTK+ will do
     // that for us (and will throw a warning if we do it!)
     gtk_notebook_remove_page( GTK_NOTEBOOK(m_widget), page );