Fix zipped_file pattern so that filenames in ZIP file are matched

This fixes a bug in the crowdin-cli tool:

Filenames in the ZIP file look like this: "<lang-code>/<original-filename>", however crowdin-cli tried to match them according to the pattern in the files.translations config (in our case it's "res/values-%two_letters_code%/%original_file_name%").

Therefore, zip filenames would never match, and translations download wouldn't work at all.