Function librdkafka_sys::rd_kafka_conf_set_dr_cb

pub unsafe extern fn rd_kafka_conf_set_dr_cb(conf: *mut rd_kafka_conf_t,
                                             dr_cb: Option<unsafe extern fn(rk: *mut rd_kafka_t, payload: *mut c_void, len: size_t, err: rd_kafka_resp_err_t, opaque: *mut c_void, msg_opaque: *mut c_void)>)