Ask for encryption passphrase when not specified in ks (#1213096)
    
    Kickstart installation fails when '--encrypted' is used without
    specifying '--passphrase'. This patch marks the storage spoke as
    unready and asks for a passphrase.
    
    Signed-off-by: Vojtech Trefny <vtrefny@redhat.com>
    
    (cherry picked from commit ca7808df44482caa6f24cb20ae09aca33194ea8d)