Distribution bars don't reappear when disabling fitted curve

[MatejBevec]

What's wrong?

In the Distributions widgets, you can end up with an empty canvas by selecting a curve fit with "fitted distributions", hiding the histogram bars with "hide bars", then disabling the curve fit again. Even though the canvas is empty, the "hide bars" checkbox appears unchecked.

How can we reproduce the problem?

1. Open the Distributions widget with some data.
2. Select any of the available functions under "Fitted distribution".
3. Check "Hide bars". The histogram bars disappear, leaving only the fitted curve(s).
4. Disable the fitted curve by selecting None under "Fitted distribution". The curve disappears, but the bars do not reappear, leaving an empty canvas. Despite this, the "Hide bars" checkbox appears unchecked.

What's your environment?

• Operating system: Windows 11
• Orange version: 3.38.0.dev0+e045632
• How you installed Orange: from source