Fix name_when_new validation message (#170)

Author: chloerei

app/presenters/hotwire_combobox/component.rb

@@ -206,7 +206,7 @@ def name_when_new_on_multiselect_must_match_original_name
 
       unless name_when_new.to_s == hidden_field_name
         errors.add :name_when_new, :must_match_original_name,
-          message: "must match the regular name ('#{name}', in this case) on multiselect comboboxes."
+          message: "must match the regular name ('#{hidden_field_name}', in this case) on multiselect comboboxes."
       end
     end