Fixes another typo bug in the LIBDIR install path

Change-Id: I5a7bf6045d51189f2fba5fae0b66cbbebeadbe2b
Signed-off-by: Luís Pereira <luis.artur.pereira@gmail.com>
Reviewed-by: David Faure KDE (deprecated, use kdab instead) <faure@kde.org>