text: Title: Number of features remains disabled when Suggest features is closed during search
  Body: ![suggest features](https://github.com/biolab/orange3/assets/5299789/8fd3572d-3564-45b0-b4ea-a0a23dea0cfa)
  
  How to reproduce:
  1. open _Suggest features_ and run
  2. close while running
  3. choose another mode (circular, LDA or PCA)
  4. open _Suggest features_: the _Number of variables_ field is disabled despite no search running
  
  OS: Windows 10 x64
  Orange: 3.35.0