Show disabled interface when it was already part of interface group, it avoids to show a random interface instead and let user to add it by mistake. It should fix #3680
Related issues
Bug #3680: disabling an interface which is part of an interface group puts another (arbitrary) interface into the group instead
Show disabled interface when it was already part of interface group, it avoids to show a random interface instead and let user to add it by mistake. It should fix #3680