OpenStack: Allow to provide both tenant name and id

When sourcing an OpenStack rc file, both variables OS_TENANT_ID
and OS_TENANT_NAME are defined.

Signed-off-by: Vincent Giersch <vincent.giersch@ovh.net>
OpenStack: Switch some Info log to Debug

Allow to use $(machine url) without having to pipe the
result due to too verbose Info logs.

Signed-off-by: Vincent Giersch <vincent.giersch@ovh.net>