listing with --human-readable can stack trace

If an image is created using the v2 cli targeted at a kilo server:

 $ glance --os-image-api-version 2 image-create --disk-format raw --container-format bare
 +------------------+--------------------------------------+
 | Property | Value |
 +------------------+--------------------------------------+
 | checksum | None |
 | container_format | bare |
 | created_at | 2015-09-14T17:12:33Z |
 | disk_format | raw |
 | id | 898cb887-bb04-41e0-98d1-7a76f389760b |
 | min_disk | 0 |
 | min_ram | 0 |
 | name | None |
 | owner | 0d1e2841f77e4936816d93e6cf252098 |
 | protected | False |
 | size | None |
 | status | queued |
 | tags | [] |
 | updated_at | 2015-09-14T17:12:33Z |
 | virtual_size | None |
 | visibility | private |
 +------------------+--------------------------------------+

listing with human readable produces the following error

 $ glance --os-image-api-version 1 image-list --human-readable
 float argument required, not NoneType

$ glance --debug --os-image-api-version 1 image-list --human-readable
curl -g -i -X GET -H 'Accept-Encoding: gzip, deflate' -H 'Accept: */*' -H 'User-Agent: python-glanceclient' -H 'Connection: keep-alive' -H 'X-Auth-Token: {SHA1}d87b9a1a03fa8906fab27558aae2f6727fe5e063' -H 'Content-Type: application/octet-stream' http://10.0.0.85:9292/v1/images/detail?sort_key=name&sort_dir=asc&limit=20

HTTP/1.1 200 OK
date: Mon, 14 Sep 2015 17:14:33 GMT
connection: keep-alive
content-type: application/json; charset=UTF-8
content-length: 897
x-openstack-request-id: req-req-1c04d92c-f838-456d-a2fe-4327bb915823

{"images": [{"status": "queued", "deleted_at": null, "name": null, "deleted": false, "container_format": "bare", "created_at": "2015-09-14T17:12:16.000000", "disk_format": "raw", "updated_at": "2015-09-14T17:12:16.000000", "min_disk": 0, "protected": false, "id": "b4830564-493f-4091-9fc8-54ac9e34f65e", "min_ram": 0, "checksum": null, "owner": "0d1e2841f77e4936816d93e6cf252098", "is_public": false, "virtual_size": null, "properties": {}, "size": 0}, {"status": "queued", "deleted_at": null, "name": null, "deleted": false, "container_format": "bare", "created_at": "2015-09-14T17:12:33.000000", "disk_format": "raw", "updated_at": "2015-09-14T17:12:33.000000", "min_disk": 0, "protected": false, "id": "898cb887-bb04-41e0-98d1-7a76f389760b", "min_ram": 0, "checksum": null, "owner": "0d1e2841f77e4936816d93e6cf252098", "is_public": false, "virtual_size": null, "properties": {}, "size": null}]}

Traceback (most recent call last):
  File "/mnt/sam/git/python-glanceclient/glanceclient/shell.py", line 700, in main
    args.func(client, args)
  File "/mnt/sam/git/python-glanceclient/glanceclient/v1/shell.py", line 123, in do_image_list
    utils.print_list(images, columns)
  File "/mnt/sam/git/python-glanceclient/glanceclient/common/utils.py", line 183, in print_list
    for o in objs:
  File "/mnt/sam/git/python-glanceclient/glanceclient/v1/shell.py", line 119, in <genexpr>
    images = (convert_size(image) for image in images)
  File "/mnt/sam/git/python-glanceclient/glanceclient/v1/shell.py", line 116, in convert_size
    image.size = utils.make_size_human_readable(image.size)
  File "/mnt/sam/git/python-glanceclient/glanceclient/common/utils.py", line 315, in make_size_human_readable
    padded = '%.1f' % size
TypeError: float argument required, not NoneType
float argument required, not NoneType