Set translation fallback to use English (so UI does not show i18n keys)

[bklang]

Doc: https://github.com/jamesarosen/ember-i18n/wiki/Doc:-Missing-Translations
Code: https://github.com/rubyforgood/Flaredown/blob/master/frontend/app/utils/i18n/missing-message.js

Here is an old issue that appears relevant: jamesarosen/ember-i18n#256

[bklang]

[bklang]

On further investigation, the translations actually occur in the backend, and not in the frontend (Ember). The translation only took effect when I changed my country, and seems to ignore any locale hint provided by the browser/device.

[bklang]

Found the source of the problem: the frontend requests a list of sexes via API, and the API is returning these malformed strings. This likely affects multiple endpoints. I'm working on a PR which will handle this more gracefully.