Fixed creating bond interface (slaves)

- Slaves can be only interfaces with bootproto=none but WebYast
  handles 'no configuration' the same way
- If interface that has no configuration is used, it has to be
  configuredd with bootproto=none later
Merge pull request #57 from kobliha/Webyast-1.3

Then let's merge it. I'm also working on extended solution now.