Changed the address of metadata server so it could be understood by
both Amazon and Openstack at the same time (and maybe Eucalyptus).

You can see it here:
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AESDG-chapter-instancedata.html
http://docs.openstack.org/trunk/openstack-compute/admin/content/metadata-service.html
http://www.ducea.com/2009/08/17/using-instance-specific-metadata-in-eucalyptus/