This latest update include a reviewed french file for the user interface.
Alternatively it is very simple to add / update a language to your camera:
Take the updated file, like this lang_french.js and upload it to www folder via FTP
Verify the result by accessing the login page of the camera (no reboot necessary)
If the French language does not appear in the language list of the login page,
ensure that lang.js (also in www) contains the following line at the end, and that it's not commented: