Redmine

When operating in sudo mode and going through the password confirmation page, editing or deleting a group results in a different redirect from when not in sudo mode.

Steps to reproduce (Edit)
1. Edit the group name on /groups/[id]/edit and submit the form.
2. Enter the password on the password confirmation page and submit the form.
3. The user is redirected to /groups/[id].
Expected result: The user is redirected to /groups/[id]/edit, as when not in sudo mode.

Steps to reproduce (Delete)
1. Click "Delete" on /groups.
2. Enter the password on the password confirmation page and submit the form.
3. The user is redirected to /groups/[id], which has already been deleted, and a 404 page is displayed.
Expected result: The user is redirected to /groups, as when not in sudo mode.

A patch that fixes this issue is attached.
The current implementation determines the redirect destination by referring to the Referer header, but I think the Referer header should not be necessary for this.