middle-mouse-click does not terminate open files when they are in a group! You should trigger exactly right on the x icon to close a window! This is a awkward!

It can terminate the whole group, but it can not terminate per each file in a group.

Here is my task-manager config: http://image.prntscr.com/image/a195c14eff854abfb4dc6683be944a41.png

Reproducible: Always

Steps to Reproduce:
0. Choose 'Close Window or Group' for 'On middle-click' in task manger settings.
1. Enable 'Grouping' in task manger settings (And ticked of the 'Only when the task manager is full' option)
2. Open some same files (Try to open some new kwrite)
3. Keep mouse on the group to see instances, then try to close one by middle-click --> that does not work here;


Expected Results:  
When we define 'Close Window or Group' in task manger settings for the option 'On middle-click', it's expected to close thing by middle-click even parts of a group one-by-one.