Fix VIF: ignore predictors that were dropped (eg. constant)
Fix VIF: ignore predictors that were dropped (eg. constant)

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