Print build date and time of firmware to upload

esp32/host/upload-via-mqtt.sh

@@ -17,6 +17,8 @@ if [ ! -f $firmwareFile ]; then
 	echo "the script $0 must be started in host/ sub directory"
 	exit 2
 fi
+echo "Firmware changed:"
+ls -l $firmwareFile
 
 mosquitto_pub -h $mqttHost -t "${mqttPrefix}${homieId}/stay/alive/set" -m "1" -r
 echo "Waiting ..."