pagure / staging: combine certs to 1, clean up logic
    
    There's no reason to not just use one letsencrypt cert for stg.pagure.
    Also clean up logic in the web config and make sure all the servernames
    are handled correctly.
    
    Once this works, will roll this to production.
    
    Signed-off-by: Kevin Fenzi <kevin@scrye.com>