Tor Egil Hoftun Kvæstad

###### Motivation for this change After #2247 was merged, it is now possible to add multiple `org-roam-backlinks-section`s to `org-roam-section`, using different functions to filter the backlinks in the different sections....

If the user inputs an invalid number (something that causes a ValueError because it can't be converted to a float), set the number back to the previous value, and discard...

If you have set makehuman to show the sliders' edit widgets, and enter an invalid number into the textfield (something that can't be converted to a float), makehuman instantly crashes....