[Bug 1071055] Adding Estonian (et), Frisian (fy-NL), Gujarati (gu-IN), Urdu (ur) Locales

You can't modify migration files. They won't be run again, and so you'll break everything if you change old ones. Instead you need to make a new migration. You can read more about that in [the developer docs](http://kitsune.readthedocs.org/en/latest/development.html#changes-that-involve-database-migrations).