This version introduced the network_data.json file, and is supported by
cloud-init 0.7.9. Cloud-init 0.7.9 will always prefer a versioned
metadata to 'latest', which in this case forces the use of the
2012-08-10 Folsom version, which does not provide network_data.json.
Change-Id: I3a604c170e124de3bbbe95f002d14439c138ca3e
Closes-Bug: #1742957