Distributions: show probabilities upon selection

[ajdapretnar]

Orange version

3.5.dev

Expected behavior

When selecting Show probabilities the probability line(s) are immediately displayed.

Actual behavior

The lines are not immediately displayed. One needs to switch the visualization to see probabilities. Re-drawing the plot should be run upon selection.

Steps to reproduce the behavior

File - Distributions. Press Show probabilities.

Additional info (worksheets, data, screenshots, ...)

[jerneju]

My bad. This issue occurred because of my wrongly made PR #2383 .