#24 Cannot delete subnet in the n-file

[Mathieu Lemay]

When we would like to delete subnet in n-file, the
subnet is deleted in the GUI, but it's not deleted in
the n-file (see directly the xml language).

Exemple:

1. open n-file which it containts many subnet.
2. delete a subnet. The subnet disappears in the GUI.
3. save the subnet.
4. open the n-file with a text editor to see file in
   xml language. The deleted subnet still exists !

Please refert to me for any questions.
Thanks