CDC #321 - Fixing a bug that occurs in the export process when a user…

…_defined value is nil

app/services/core_data_connector/export/base.rb

@@ -44,7 +44,7 @@ def to_export_csv(user_defined_fields)
         private
 
         def add_user_defined_fields(hash, user_defined_fields)
-          return unless user_defined_fields.present? && self.respond_to?(:user_defined)
+          return unless user_defined_fields.present? && self.respond_to?(:user_defined) && self.user_defined.present?
 
           user_defined_fields.each do |user_defined_field|
             key = ImportAnalyze::Helper.uuid_to_column_name(user_defined_field.uuid)