locales: remove unused carrierwave localisation
locales: remove unused carrierwave localisation

- It was broken since the renaming of `extension_white_list` to
  `extension_whitelist` (f0ed61cce8e7faae90a3b3923eedc17a27118023)
- The localisation is already included in the `carrierwave-i18n` gem
- The localisation included in the gem is better than ours (it mentions
  which extensions are allowed).
sgmap/tps,sgmap/tps,sgmap/tps