Enable AWS IoT and MQTT TLS on Tasmota for ESP8266 devices.

The firmware is built automatically via GitHub Actions using latest Tasmota release and the following build flags:

-DUSE_MQTT_TLS 
-DUSE_MQTT_AWS_IOT_LIGHT 
-DUSE_MQTT_TLS_CA_CERT

• Create a backup of your current device by going to Tasmota's WebUI -> Configuration -> Backup configuration
• Download latest built firmware tasmota-aws-iot.bin.gz
• Open your Tasmota's webUI and go to Firmware Upgrade -> Choose file and select tasmota-aws-iot.bin.gz
• Wait until upgrade is over and that your device has rebooted

In case uploading the firmware fails with "Not enough space" error, follow these steps:

• Upgrade via OTA to tasmota-minimal using this URL:
  • http://ota.tasmota.com/tasmota/release/tasmota-minimal.bin.gz
• Wait till reboot
• Repeat Firmware Upgrade -> Choose file -> tasmota-aws-iot.bin.gz

• Setup your device and AWS IoT Authorizer following AWS IoT Tasmota documentation
• Once MQTT TLS is setup on the device, reboot
• When device boots expect a similar result in Tasmota's WebUI -> Console (example for Athom Plug V2)

MQT: Attempting connection...
MQT: TLS connected in 1753 ms, max ThunkStack used 4596
MQT: MFLN not supported by TLS server
MQT: Connected

• From AWS IoT Core -> MQTT test client subscribe to the topic tele/tasmota_XXXX/SENSOR
• You should start receiving device messages in MQTT test client console

• Open your Tasmota's WebUI and go to Firmware Upgrade -> OTA and Start Upgrade using the default OTA URL.