Allow to show canvas graph bars according the precipitation probability

[dbustosrc]

First of all, thank you for keeping this alive and attending feature request, I really like this project

Is your feature request related to a problem? Please describe.
The last update 2.4.0 removed the option to have canvas graph bars according the precipitation probability, and now the only option available is rainfall in mm metric

Describe the solution you'd like
Allow to show canvas graph bars according the precipitation probability.

Additional context
As you can see in the screen capture, the graph bars is showing rainfall in mm metric.