Trigger firmware update via MQTT. (ESP Only)

[h2zero]

If enabled in user_config.h this will trigger the OMG to update it's firmware from the link
provided in the MQTT message.

Example message:

{"version": "test ",
 "password": "OMGPASSWORD",
 "url": "https://github.com/1technophile/OpenMQTTGateway/releases/download/v0.9.6/esp32dev-ble-cont-firmware.bin"
}

If the firmware version in the message is not the same as the current OMG version the device will self update using the link in the url of the message.

[1technophile]

Would be nice to update the docs also:
https://docs.openmqttgateway.com/use/gateway.html

[1technophile]

I think defining 2 test environments (ESP32 & ESP8266) could help for the CI of this, here is an example:

OpenMQTTGateway/platformio.ini

Line 825 in 4706d75

[env:esp32dev-tls-test]

Or we may update these ones so that they cover also OTA

[h2zero]

Would be nice to update the docs also:
https://docs.openmqttgateway.com/use/gateway.html

Yes that can be done as well, once the process is finalized. I think adding a port parameter to the JSON message should be added and therefore would need to be documented as well.

[h2zero]

I think defining 2 test environments (ESP32 & ESP8266) could help for the CI of this, here is an example:

OpenMQTTGateway/platformio.ini

Line 825 in 4706d75

[env:esp32dev-tls-test]

Or we may update these ones so that they cover also OTA

Good plan, will do.