7ce2861 Add a button to show the inactive milestones

Authored and Committed by pingou 2 years ago
    Add a button to show the inactive milestones
    
    It can be useful to turn them back on or just to check if they exists
    or not.
    
    Fixes https://pagure.io/pagure/issue/3587
    
    Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>