"Undo Close Tab" assigns tab to wrong tab group

[SuperTux88]

Steps to reproduce:

1. Open two tab groups with some tabs.
2. Close a tab in group 1.
3. Switch to group 2.
4. Click "Undo Close Tab".

Actual Results:

The tab opens in the current group, but is still assigned to group 1.

Expected Results:

The tab should be assigned to the current group. (Same behavior as Panorama)