Updating the minimal required version number for kdelibs, inside kdebase

[David Faure]

I committed a variant of this patch now.

-- 
David Faure, faure-RoXCvvDuEio at public.gmane.org, sponsored by Qt Software @ Nokia to work on KDE,
Konqueror (http://www.konqueror.org), and KOffice (http://www.koffice.org).