Sensor value not reset when changing field.

[CarlosWilkes]

There is a bug in the cycling power default where:

1 - Edit Speed field.
2 - Change Sensor from best to something else (e.g. my Bluetooth speed sensor).
3 - Change Speed field to something else (e.g. time total).

This new data field attempts to read from the previously set sensor, but this sensor of course gives no meaningful data. Additionally, from this new field I can no longer change the sensor. To fix this I must change the data field back to Speed, reset the Sensor to best, then change the field to time total.