Missing EO locale in kde. http://l10n.kde.org/team-infos.php?teamcode=eo page shows there is one.
It appears the Esperanto translation was not released since KDE/4.5 due to lack of maintenance. According to the latest stats, the translation is only currently 36.25% complete.
If you speak this language, I am sure upstream would be happy to work with you to improve the translation in order to get it included in a future release.