Set the correct device names for "fixed" and "public"

Since https://github.com/crowbar/barclamp-deployer/pull/147 was merged the
deployer barclamp automatically include the vlan id in the interface attribute.
This should fix linux-bridge support again, which was broke since the above
mentioned pull request.
Merge pull request #211 from rhafer/release/pebbles/master

Set the correct device names for "fixed" and "public"