message: Fix index for switch_multilevel
diff: @@ -574,6 +574,7 @@ Gateway.prototype.discoverValue = function (node, valueId) {
  // cfg.discovery_payload.position_closed = valueId.min || 0
  // cfg.discovery_payload.position_topic = this.mqtt.getTopic(topic)
  // cfg.discovery_payload.set_position_topic = cfg.discovery_payload.position_topic + '/set'
  + if (valueId.index === 0) { // brightness level
  cfg = Object.assign({}, hassCfg.light_dimmer)
  cfg.discovery_payload.brightness_scale = valueId.max || 255
  cfg.discovery_payload.state_topic = this.mqtt.getTopic(topic)
  @@ -582,6 +583,9 @@ Gateway.prototype.discoverValue = function (node, valueId) {
  cfg.discovery_payload.state_value_template = `{{ 'off' if value_json.value == 0 else 'on }}`
  cfg.discovery_payload.command_off_template = '{"value": 0}}'
  cfg.discovery_payload.command_on_template = `{"value": ${valueId.max || 255}}`
  + } else {
  + return
  + }
  break
  case 'sensor_binary':
  // try to guess the type
  