Comment 3 for bug 1621490

Over the course of reviewing this patch, I ran this migration at least once on a system that had existing networks. Since it was an ML2 based system, it would've had networksegments to migrate. But, now I'm second guessing myself and I'm not sure that I tested the version that merged. :( Now, I'm wondering what happened. I can spend a little bit of time on this. I'm also wondering why grenade wouldn't have caught this problem.