Debian: Use different paths for KDC cert and key
    
    Co-authored-by: Timo Aaltonen <tjaalton@debian.org>
    Signed-off-by: Christian Heimes <cheimes@redhat.com>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>