collectd plugins for OpenStack do not support Keystone v3/auth

[Swann Croiset]

For example with cinder plugin:

 Import "openstack_cinder"

 <Module "openstack_cinder">
   KeystoneUrl "http://keystone-ip:5000/v3/auth"
   MaxRetries "2"
   Password "xxxx"
   Tenant "services"
   Timeout "20"
   Username "nova"
 </Module>

http://keystone.fuel.local:5000/v3/auth/tokens responded with status code 400
[2017-02-21 12:56:29] Cannot get a valid token from http://keystone.fuel.local:5000/v3/auth