i think this works fine, tough the code is now more complicated than it needs to be i think. the `django.conf import settings` should never fail now, and it seems like we would raise an attribute error if `PREVIEWER_RE` wasn't defined (which was what it looks like the import was designed to originally test). so i think should either add that check back, or at a minimum remove the try/except and then assume we're always defining that (in which case I'd add it to our default `settings.py` file too)