fixed recursion issue in searching mapping model

[samnung]

[NSMappingModel mappingModelFromBundles:@[[NSBundle mainBundle]]
                         forSourceModel:sourceModel
                       destinationModel:model];

when params sourceModel and model are equal (v2), this method returns mapping model from v2 to v3

see this diff https://gist.github.com/pnc/2321704

[samnung]

@jnagel33 sorry, it is quite time since I used this thing. Did you try mine version of the migrator? It should fix the recursion problem.

[jnagel33]

@samnung No worries, I figured it was a long shot. I have only seen the issue once ever so it's not easily reproducible. That's why I was curious if you knew of a scenario that caused this. I will probably end up adding this code since I don't think will negatively impact anything. Thanks