Use correct var names when reading the config.

[ezio-melotti]

This PR fixes two issues that prevented the server from running properly:

• sioserver.py is currently looking for name and description in the config, even though we settled on name and desc
• the sensor_infos use sensor_name and sensor_desc, so when comparing with those, the sensor_ prefix is added

The logic also seems backward, since the sensor_info values take precedence over the config file, whereas it should be the opposite. I'll fix this in a separate PR after some additional testing.

[ezio-melotti]

Good catch, I now fixed it.