links section is incorrect when listing trusts

[Steve Martinelli]

This error is only seen when calling GET /OS-TRUST/trusts, so listing all trusts.

(Pdb) p r.result
{u'links':
  {u'self': u'http://localhost:5000/v3/OS-TRUST/OS-TRUST/trusts',
  u'next': None,
  u'previous': None},
u'trusts':
  [{u'impersonation': False,
  u'trustor_user_id': u'e50e25ed5a50499ab5b662b008295b54',
  u'description': u'2691267f81144712bea98d3521cf58e4',
  u'links': {u'self': u'http://localhost:5000/v3/OS-TRUST/trusts/fdfd22aebae4498b9df65e0af8821d5b'},
  u'enabled': True,
  u'expires_at': None,
  u'trustee_user_id': u'a6a165d04bed417bb24f3bcb5ab89dfd',
  u'project_id': u'b69e4616a2124f4f98733bea8a3a8ef4',
  u'id': u'fdfd22aebae4498b9df65e0af8821d5b',
  u'name': u'6a43b19df472432b9cc0e37bfc6c0a0b'}]}

(Pdb) p r.result['links']
{u'self': u'http://localhost:5000/v3/OS-TRUST/OS-TRUST/trusts', u'next': None, u'previous': None}

The resulting url for links of the entire collection is incorrect, it has an extra OS-TRUST.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/72580
Committed: https://git.openstack.org/cgit/openstack/keystone/commit/?id=674bd23c216874f2449e1585f9c0d074b4096b7b
Submitter: Jenkins
Branch: master

commit 674bd23c216874f2449e1585f9c0d074b4096b7b
Author: Steve Martinelli <email address hidden>
Date: Tue Feb 11 02:01:29 2014 -0600

    List trusts, incorrect self link.

    Fix the base_url method in trust controller to build off
    of the one in V3 controller.

    Closes-Bug: #1279398

    Change-Id: If9b3114c9b2b9978237988fa3b52e0bede783057