message: fix: /health return 200 if mqtt is disabled
  Fixes
diff: @@ -213,10 +213,15 @@ app.get('/health', async function (req, res) {
  let zwave = false
  if (gw) {
  - mqtt = gw.mqtt ? gw.mqtt.getStatus().status : false
  + mqtt = gw.mqtt ? gw.mqtt.getStatus() : false
  zwave = gw.zwave ? gw.zwave.getStatus().status : false
  }
  + // if mqtt is disabled, return true. Fixes #469
  + if (mqtt) {
  + mqtt = mqtt.status || mqtt.config.disabled
  + }
  +
  const status = mqtt && zwave
  res.status(status ? 200 : 500).send(status ? 'Ok' : 'Error')
  