fix df_self_checks (reading config variables)
fix df_self_checks (reading config variables)

LREN-CHUV/data-factory-airflow-dags,LREN-CHUV/airflow-mri-preprocessing-dags,LREN-CHUV/airflow-mri-preprocessing-dags,LREN-CHUV/data-factory-airflow-dags