Fix #1197 breaks SelectedCount and painting of selected rows with panning selection

[kuola]

The fix for #1197 is breaking SelectedCount for selecting/deselecting rows with panning selection. V8.3 code.

The selected count decreasing more than what is selected.
Reproduce steps:

• Load project Demos\Advanced
• Start "The speed breakthrough"
• Add 100 nodes
• Select all (with ctrl+a). -> Selected: 100
• With ctrl pressed, start deselecting rows with panning selection.
  • When deselecting one row, the selected count decreases by 2

The other "effect" which can be seen is that the paint for selection doesn't work:

• Load project Demos\Advanced
• Start "The speed breakthrough"
• Add 100 nodes
• Start panning selection from somewhere in the middle of the lise (like index 10)
• While keeping the panning selection going, move the mouse pointer up and down in the list. What happens is that after repating this couple of times, you will get ghosted selections on the list. And after this has happened, if you do ctrl+a to select all, the selected count is not 100.

If I comment out the row from the mentioned fix, then the selection and paint seems to work correctly.