Fix plot() for GLM-ordinal
Fix plot() for GLM-ordinal

- ordinal family is only supported in GLM, no need to check that
- scoring history only has "negative_log_likelihood" and "objective"

michalkurka/h2o-3,michalkurka/h2o-3,h2oai/h2o-3,h2oai/h2o-3,michalkurka/h2o-3,michalkurka/h2o-3,h2oai/h2o-3,h2oai/h2o-3,h2oai/h2o-3,michalkurka/h2o-3,michalkurka/h2o-3,michalkurka/h2o-3,h2oai/h2o-3,h2oai/h2o-3,h2oai/h2o-3