Cannot switch back to default profile if Northstar wasn't installed

[GeckoEidechse]

To reproduce

1. Select a valid Titanfall2 install (easiest is to fake one with just touch Titanfall2.exe in some directory)
2. Manually create a new profile in there (e.g. mkdir --parents my-profile/mods)
3. Select that Titanfall2 "install" in FlightCore
4. Switch profile to my-profile
5. You can no longer switch back to R2Northstar

Easiest solution would be to always consider have R2Northstar in the return of fetching profiles and always have R2Northstar be considered a valid profile.

[GeckoEidechse]

cc @Jan200101

[Jan200101]