Fix bug in healing on Azure

Healing operation doesn't work with VMs deployed on Azure due to lack of
information in vnfrs requiered for the operation. That data must be
provided by the 'refresh_vms_status' method in the connector.

Change-Id: I915a0c7136e7a16729d0aba4357670dd28b66847
Signed-off-by: aguilard <e.dah.tid@telefonica.com>