MQTT Version breaks Docker container

[kaba72]

Hi, I've been running solariot for a couple of years without issues using the meltaxa/solariot container. Never had to change anything.
When the container updated tonight, it broke due to an incompatibility between the python mqtt library and the current code.

The container keeps aborting with an error the moment it tries to create the mqtt client object.
I believe the issue is best described here: https://stackoverflow.com/questions/77984857/paho-mqtt-unsupported-callback-api-version-error

That is the exact same error message I see in the logs. Looks like it might be a one-line/one-word fix in the solariot code.

Thanks for this piece of software - find it extremely helpful.

Regards,
Karsten

[zyrorl]

PR is raised to fix this #108