list of attached volumes in nova show is unreadable

Description of problem:
The implementation of the the RFE Bug 978519 is problematic:

The list of the volumes attached is presented in the 'nova show' output as a list of dictionaries, like so:

os-extended-volumes:volumes_attached | [{u'id': u'cfaba0b7-a578-48f3-8f2b-53b8c7f6447b'}|

The "u'id" key is irrelevant to the administrator and it is unnecessary.
When there are more than 2 volumes attached to the instance the display is unreadable:

| os-extended-volumes:volumes_attached | [{u'id': u'cfaba0b7-a578-48f3-8f2b-53b8c7f6447b'}, {u'id': u'07fd2432-3ae8-402e-acfd-fb2146942f99'}, {u'id': u'37683c4d-0bbd-4eb7-900a-cb7596375221'}, {u'id': u'554c605a-7c9b-4192-af42-3be5daf3c203'}, {u'id': u'f01fa946-a6e5-4581-ac18-f482f454794e'}] |

Version-Release number of selected component (if applicable):
openstack-nova-common-2013.2-5.el6ost.noarch
openstack-nova-network-2013.2-5.el6ost.noarch
python-novaclient-2.15.0-1.el6ost.noarch
python-nova-2013.2-5.el6ost.noarch
openstack-nova-api-2013.2-5.el6ost.noarch
openstack-nova-console-2013.2-5.el6ost.noarch
openstack-nova-compute-2013.2-5.el6ost.noarch
openstack-nova-conductor-2013.2-5.el6ost.noarch
openstack-nova-novncproxy-2013.2-5.el6ost.noarch
openstack-nova-scheduler-2013.2-5.el6ost.noarch
openstack-nova-cert-2013.2-5.el6ost.noarch

Red Hat Enterprise Linux Server release 6.5

Steps to Reproduce:
1. attach volumes to an instance
2. run nova show <instance name / uid>

Expected results:
a clean list of the uid's of the volumes attached to the instance.