Fix returning the active status of a package
    
    Well, this is embarrassing, we made the API endpoint always
    return False so we could debug the behavior of the UI in that
    situation and somehow this slipped through the PR and landed
    in a review. Quite unfornatunate.
    This commit aims at fixing this issue.
    
    Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>