Magnum does not support versionless keystone endpoint

[Michal Nasiadka]

In default installation - kolla project deploys a versionless endpoint in the service catalog:

# openstack catalog show identity
+-----------+--------------------------------------------------------+
| Field | Value |
+-----------+--------------------------------------------------------+
| endpoints | RegionOne |
| | public: https://xxx.xxx.net:5000 |
| | RegionOne |
| | admin: http://xxx.xxx.net:35357 |
| | RegionOne |
| | internal: http://xxx.xxx.net:5000 |
| | |
| id | d5ea252a181b4b2b8e6ecb51ddef4c50 |
| name | keystone |
| type | identity |
+-----------+--------------------------------------------------------+

With this in the catalog, the AUTH_URL is https://xxx.xxx.net:5000 instead of https://xxx.xxx.net:5000/v3

And the script that downloads the certificates fails, due to a problem in token fetch:

# curl -k -s -i -X POST -H "$content_type" -d "$auth_json" $url
HTTP/1.1 404 Not Found
Date: Wed, 22 Nov 2017 14:33:25 GMT
Server: Apache/2.4.18 (Ubuntu)
Vary: X-Auth-Token
X-Distribution: Ubuntu
Content-Length: 146
Content-Type: application/json

{"error": {"message": "(http://xxx.xxx.net:5000/auth/tokens): The resource could not be found.", "code": 404, "title": "Not Found"}}