Use kdesu instead of pkexec, hide non-working LUKS FDE checkbox
    
    * Sun Oct 01 2016 Kevin Kofler <Kevin@tigcc.ticalc.org> - 2.4.1-3
    - BuildRequire Qt >= 5.6, required by the locale and netinstall modules
    - Use kdesu instead of pkexec (works around #1171779)
    - Hide the LUKS full disk encryption checkbox which does not work on Fedora yet