Steps to reproduce
==================
- Go to Field Service
- Group by "start date: week"
- Archive every record in a column until there is only one left
- Go back to the kanban view
- Click on the single record from the column
- Archive it
- Using the breadcrumbs, go back to the kanban view
=> The group order is not preserverd and the empty one is the last one
Cause of the issue
==================
Before archiving the record, we have the following data:
`{group1: [1], group2: [2, 3]}`
After archiving the record, we have `{group2: [2, 3], group1: []}`
A new group is recreated from the old one, but it is always added at the
end.
Solution
========
We can insert the old group at his previous index.
The same solution was used in previous versions
opw-3816409
closesodoo/odoo#160121
X-original-commit: 0d44e931c40fbca005b8d1864cf2d07485ed84f8
Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>
Hubert Van De Walle
c6640ddafd