[fix] use ip6.yunohost.org, more reliable than ipv6.yunohost.org
[fix] use ip6.yunohost.org, more reliable than ipv6.yunohost.org

YunoHost/moulinette-yunohost,YunoHost/moulinette-yunohost,YunoHost/yunohost,YunoHost/yunohost,YunoHost/moulinette-yunohost,YunoHost/moulinette-yunohost,YunoHost/moulinette-yunohost,YunoHost/yunohost,YunoHost/yunohost