The install.php script downloaded joomla4en_cinnk.zip, which includes those two 0-byte files, so after extracting that zip file I tried running the install script. After a few moments I got "Impossible d'extraire l'archive." at the top of the same "Install Your Website" page, but just going to the root of the site gave me a loaded and ready-to-go site. The only catch --- there wasn't an installation process that let me set the admin user password. I see a user with the email address I entered in the Install page, so what's the default password? I tried blank, 'password', 'cinnk' ... my imagination fails me.
Any help? Thanks!