prefs: Don't crash in application mode

Using application mode with a desktop file doesn't give us a fully
populated profile dir don't try to continue on in this case.
3 jobs for prefs-crash in 0 seconds (queued for 89 minutes and 29 seconds)
latest
Status Job ID Name Coverage
  .Pre
failed #247363
check-code-style

failed #247364
flatpak-scanbuild

 
  Build
skipped #247365
flatpak
 
Name Stage Failure
failed
flatpak-scanbuild .Pre There has been a timeout failure or the job got stuck. Check your timeout limits or try again
No job log
failed
check-code-style .Pre There has been a timeout failure or the job got stuck. Check your timeout limits or try again
No job log