Mobile Sites No Longer Work Out Of The Box

The most recent commit on this repo breaks a lot of stuff that used to just work out of the box. WSJ and other websites now try to load the desktop view, which really sucks on a phone. Citymapper, Google Maps, and others try to guess my location (by IP address?) instead of using whatever API they used to which resulted in a fast, accurate location as one might expect on a smartphone.

Can we please revert this? I am overriding it manually for now, but the experience of a less advanced user will just be that most of the Internet is no longer usable on Firefox without hooking the phone up to a desktop monitor.