Clicking in the file system tree view, while the processing is running, stops the ability for the treeview to expand

[sparkhi]

Once a Droid identification process is started, the UI shows the folder that is being analysed. If you click on this folder before the process has finished, this folder stays highlighted but it does not update itself with the "expandable" icon and cannot be expanded. The "expand" context menu does not work either

Steps to reproduce.

1. Find a folder with large enough data to give you time to click while the process is running (I also set it to generate checksums in settings)
2. Launch Droid
3. Pick the folder to analyse
4. Click "Start"
5. As the analysis is happening and the progress bar is moving, click on the folder in the UI
6. Notice that the folder cannot be expanded any more (bug!!)
7. Even after the analysis has finished, you still cannot expand the folder!!

Observed on Linux (Ubuntu) as well as Windows