Revert "Synced code [skip ci]"

This reverts commit 036a033.

Author: ankane

lib/xgboost/model.rb

@@ -20,8 +20,6 @@ def save_model(fname)
 
     def load_model(fname)
       @booster = Booster.new(params: @params, model_file: fname)
-      config = JSON.parse(@booster.save_config)
-      load_model_attributes(config)
     end
 
     def feature_importances
@@ -31,11 +29,5 @@ def feature_importances
       total = scores.sum.to_f
       scores.map { |s| s / total }
     end
-
-    private
-
-    def load_model_attributes(config)
-      @objective = config["learner"]["objective"]["name"]
-    end
   end
 end