Comment 2 for bug 1544608

We had some discussion about this in IRC
http://eavesdrop.openstack.org/irclogs/%23openstack-dev/latest.log.html#t2016-02-11T15:18:08

my initial impression is that this is an intermittent timeout where glance takes longer than Horizon expects to create a new image.

Given that it's quite infrequent, and seems to be a test issue rather than a product issue, marking as "low" priority.