Allow reloading the same app, #22280

The exception made it impossible to use IPython autoreloading.
This error is to prevent loading of different modules (with same base name) but it also blocks autoreloading of absolutely the same app.

https://code.djangoproject.com/ticket/22280
`model.__name__` alone is not sufficient. It would need to check for equality of both `model.__name__` and `model.__module__`.