Based on my reading of [the get_lang_choices docstring](https://github.com/mozilla/bedrock/pull/1419/files#diff-e0056acf20eb2b478222ee078b282bafR26) it seems like this line should be something like
```python
newsletters = [nl.strip() for nl in newsletters.split(',')]
```
or maybe use the csv module from the standard library.

That's assuming the feature is actually needed-- if not, perhaps the docstring should be changed?