Localization files (.qm) for 5.3 not accessible (dead link)

Using Firefox, going to ftp://ftp.qt-project.org/qt/l10n/index.html to get some .qm files, I try to get 5.3 (old stable version currently) .qm file for Japanese (ftp://ftp.qt-project.org/qt/l10n/qt5-old/qt_ja.ts) but the link does not work.
Having a look to that /qt/l10n/qt5-old folder with FileZilla shows that the folder is indeed empty.