fix: typo in config file names

% openstack server list --os-cloud virtualdata
Cloud virtualdata was not found.
% mv ~/.config/openstack/cloud.yaml ~/.config/openstack/clouds.yaml
% openstack server list --os-cloud virtualdata
+--------------------------------------+----------
| ID                                   | Name     
+--------------------------------------+----------
| xxxxxxxxxxxxxxxxxxxxxxxx             | xxxx     
+--------------------------------------+----------

https://docs.openstack.org/python-openstackclient/latest/configuration/index.html