Ticket 23600

Make django.core.files.storage.default_storage take account of overriding of the following settings:

MEDIA_URL
FILE_UPLOAD_PERMISSIONS
FILE_UPLOAD_DIRECTORY_PERMISSIONS

The funky indent was to please flake8 in the first place of course! I'm not sure what is better between a local variable, as you suggest, and following the example of COMPLEX_OVERRIDE_SETTINGS and having a module level var at the top of the file. I guess the local variable keeps everything together in one place, which is nice.