refkit-image.bbclass: better error message in local_autologin
refkit-image.bbclass: better error message in local_autologin

The image feature should not be enabled when not using systemd.
Provide a better error message where it previously just failed
due to missing files.

Signed-off-by: Patrick Ohly <0fc9d825c622b2a5ac5160289c29f03654b10648@intel.com>

YinThong/intel-iot-refkit,mythi/intel-iot-refkit,YinThong/intel-iot-refkit,klihub/intel-iot-refkit,YinThong/intel-iot-refkit,mythi/intel-iot-refkit,klihub/intel-iot-refkit,mythi/intel-iot-refkit,intel/intel-iot-refkit,jairglez/intel-iot-refkit,jairglez/intel-iot-refkit,jairglez/intel-iot-refkit,mythi/intel-iot-refkit,jairglez/intel-iot-refkit,klihub/intel-iot-refkit,ipuustin/intel-iot-refkit,mythi/intel-iot-refkit,intel/intel-iot-refkit,intel/intel-iot-refkit,ipuustin/intel-iot-refkit,klihub/intel-iot-refkit,mythi/intel-iot-refkit,ipuustin/intel-iot-refkit,intel/intel-iot-refkit,intel/intel-iot-refkit,jairglez/intel-iot-refkit,YinThong/intel-iot-refkit,klihub/intel-iot-refkit,jairglez/intel-iot-refkit,YinThong/intel-iot-refkit,YinThong/intel-iot-refkit,klihub/intel-iot-refkit,YinThong/intel-iot-refkit,klihub/intel-iot-refkit,ipuustin/intel-iot-refkit,mythi/intel-iot-refkit,intel/intel-iot-refkit,ipuustin/intel-iot-refkit,intel/intel-iot-refkit,ipuustin/intel-iot-refkit,jairglez/intel-iot-refkit,ipuustin/intel-iot-refkit