Make progress in getting the quantum metadata agent functional. [1/2]

This pull request set cleans up firewalling on nova-compute nodes, and
fixes up the configuration of the quantum metadata agent.

With these changes, instances spawned in Nova get 404 errors trying to
talk to the metadata server instead of timeouts and 500 errors.  Yay progress!


 .../nova/templates/default/nova-compute.conf.erb   |    4 ++--
 .../cookbooks/nova/templates/default/nova.conf.erb |    1 -
 smoketest/00-deploy-nova-vm.test                   |   10 ++--------
 3 files changed, 4 insertions(+), 11 deletions(-)

Crowbar-Pull-ID: d2bf78a4d50c026a2d9d3e918e8280c70b543797

Crowbar-Release: pebbles