Always import the most recent translation for RKWard, instead of cached translation import

RKWard translations in craft are currently managed via an auxiliary git repository containing an export of the translation files. We'd rather like to make sure craft always uses the most recent translations by calling the project's import_translations.py-script from within craft (at the fetch-stage). This patch does that, but I'm not sure it's the cleanest way to accomplish that.

Note that import_translations.py will become much faster following education/rkward!2 (merged) , which is the original motivation for this request.