"openstack image show <non-ASCII>" fails

Issue

• Something goes wrong when trying to display information about an image using a name that contains non-ASCII letters. Using the id instead works, but I have problems remember those.

$ openstack image list 
+--------------------------------------+----------+
| ID                                   | Name     |
+--------------------------------------+----------+
| 7215b7b1-233f-42e0-a0f6-4a6b5b86e9a4 | RHEL 6.6 |
| f522abf7-4b0a-4dc7-9043-bac3b6d7c468 | F22α     |
| 4ae3b8ea-41da-4273-8051-08a85c00fd01 | CentOS6  |
| 3eebc913-1111-4707-9320-0a8768f2a2fe | F21      |
| ea779cb7-0374-47b8-a26f-a89717cf689b | CoreOS   |
| 23db74a9-da6c-4bb2-a931-9393f0f2706c | RHEL 7.0 |
| 2e8c6675-1adc-41f0-9642-8a602111f283 | cirros   |
+--------------------------------------+----------+
$ openstack image show F21 # Works fine
+------------------+--------------------------------------+
| Field            | Value                                |
+------------------+--------------------------------------+
| checksum         | d009530079fd6567a3f0579a09c03af0     |
…
| virtual_size     | None                                 |
+------------------+--------------------------------------+
$ openstack image show F22α # But this one doesn't work.
/usr/lib/python2.7/site-packages/openstackclient/image/client.py:113: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal
  for (attr, value) in searches):
ERROR: openstack No image with a name or ID of 'F22α' exists.