That has nothing to do with my code. The binding only subscribes to the mqtt broker so has no effect on it.
There was some “smart quotes”: “” and it should be:"" in the item
This is because you are not using the How to use code fences
Your item should be:
Number:Temperature Sonoff_Temp_Test "Temperature Sonoff [%.1f °C]" { mqtt="<[openmqtt:tele/Sonoff_Temp_1/SENSOR:state:JSONPATH($.DS18B20.Temperature)]" }