Comment 6 for bug 1712463

To be more specific about the preceding comment:

In the Tasks controller, when I put a pool.waitall() after this line, the import task is executed (it goes to 'failure', but that's because of the oslo_concurrency problem; the key thing is that it gets out of 'pending'):
http://git.openstack.org/cgit/openstack/glance/tree/glance/api/v2/tasks.py?h=stable/pike#n82