Fix for #82: ignoring network_id if using Basic networking

[nicolasbrechet]

Network ID shouldn't be used with Basic Networking, so if we're using Basic Networking and a network_id is set, we should just ignore it.

This should not change anything if Advanced Networking is used, or if no network ID is set when using Basic Networking.

[miguelaferreira]

Hi @nicolasbrechet

Thanks for the PR.
@bheuvel found a way to query the needed information for network type and security groups from the cloud itself (using the fog library).

Could you please test his PR (#134) to see if his solution will fix the problem you found?

[miguelaferreira]

Closing this PR since it has been addressed in PR #134