Incorrect message: "Error: Failed to delete subnet" when deleting port

[Julie Pichon]

When trying to delete a port that is in use, Horizon shows the message "Failed to delete subnet <id>".

Using the command-line, Neutron shows the following error:

409-{u'NeutronError': {u'message': u'Port <id> has owner network:router_interface and therefore cannot be deleted directly via the port API.', u'type': u'L3PortInUse', u'detail': u''}}

We should fix the message. It looks like it's just a typo: https://github.com/openstack/horizon/blob/master/openstack_dashboard/dashboards/admin/networks/ports/tables.py#L41

To reproduce:
- Create a network and subnet
- Create a router
- Go to the router's detail and add an interface to the previously created subnet
- In the admin dashboard, go to Networks -> <that new network> -> Ports and try to delete the router

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/58781

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/59002

[Julie Pichon (jpichon)]

The status will be automatically updated when the patch is merged into the repository, please do not update it yourself before this has happened. Thank you.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/59002
Committed: http://github.com/openstack/horizon/commit/059b75625c4f0b022047c0b5996eeee5df2194d4
Submitter: Jenkins
Branch: master

commit 059b75625c4f0b022047c0b5996eeee5df2194d4
Author: Thomas Stenberg <email address hidden>
Date: Thu Nov 28 13:28:31 2013 +0100

    Corrected incorrect message when deleting port.

    Updated the file /horizon/openstack_dashboard/dashboards/admin/
    networks/ports/tables.py so it will give the correct error message
    when trying to delete a port that is in use.This updated error
    message will give the same information as when using the command-line.

    Change-Id: I62c0fb1c5b9b073c0d083bddc45133d502b554be
    Closes-Bug: #1251314