Mini_suffix and "unknown file type"

Let me know if the following commits do not fix it. I hope no one is developing on windows :wink:

https://github.com/discourse/mini_suffix/commit/5dc77c137cacbdc6d53b71804c58eac558933c0c

https://github.com/discourse/discourse/commit/30534993759f39ae5b490fcc2d7f875c1590fc1d