extmod/modbluetooth: Ignore unused self_in in ble_gatts_indicate.

extmod/modbluetooth.c

@@ -673,6 +673,7 @@ STATIC mp_obj_t bluetooth_ble_gatts_notify(size_t n_args, const mp_obj_t *args)
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(bluetooth_ble_gatts_notify_obj, 3, 4, bluetooth_ble_gatts_notify);
 
 STATIC mp_obj_t bluetooth_ble_gatts_indicate(mp_obj_t self_in, mp_obj_t conn_handle_in, mp_obj_t value_handle_in) {
+    (void)self_in;
     mp_int_t conn_handle = mp_obj_get_int(conn_handle_in);
     mp_int_t value_handle = mp_obj_get_int(value_handle_in);