Run 'rpm -qlp LPRng' and look at the last line: usr/src/build/192887-i386/install/usr/share/locale/fr/LC_MESSAGES/LPRng.mo Huh? That can't be the right path to install the .mo files to...
Oops.
Fixed package is LPRng-3.8.19-3.
Fix confirmed with 3.8.19-3.