notebook: redraw arrows after closing a tab

Thanks to Daniel Boles for helping with a crash in an earlier version of
this patch.

https://bugzilla.gnome.org/show_bug.cgi?id=777547

gtk/gtknotebook.c

@@ -4950,6 +4950,8 @@ gtk_notebook_real_remove (GtkNotebook *notebook,
   gtk_notebook_update_labels (notebook);
   if (need_resize)
     gtk_widget_queue_resize (GTK_WIDGET (notebook));
+  if (!destroying && priv->scrollable)
+    gtk_notebook_redraw_arrows (notebook);
 }
 
 static void