publish version on startup

src/main.cpp

@@ -607,6 +607,12 @@ void setup()
   if (!ota.getMAC().equals("246f28d1a080")) mqtt.subscribe("thomas/sensor/246f28d1a080/#", receiveMqtt);
   if (!ota.getMAC().equals("30aea47b0568")) mqtt.subscribe("thomas/sensor/30aea47b0568/#", receiveMqtt);
 
+  /* temp: publish version */
+  delay(5000);
+  String topic_version = String("thomas/sensor/") + ota.getMAC() + String("/version");
+  const char* fw_version_str = String(FW_VERSION).c_str();
+  mqtt.publish(topic_version.c_str(), fw_version_str, strlen(fw_version_str));
+
   ESP_LOGD(TAG, "setup done");
 }