Xen host default image is not the same as in Advertisment RSpec

[lnevers@bbn.com]

Ran a test which requested 2 Xen VM without specifying a disk_image to verify the default OS allocation. On the allocated nodes I found:

    xen1:~% cat /etc/issue
    Ubuntu 12.04 LTS \n \l

In the Advertisement RSpec for the Xen server pc3, I see the following default disk_image:

<disk_image default="true" description="Generic osid for openvz virtual nodes." 
name="urn:publicid:IDN+utah.geniracks.net+image+emulab-ops:OPENVZ-STD" 
os="Fedora" version="15"/>

The advertisement should match the version actually used by default.