[ux] make dns-conf help sentence obvious that it's a sample conf
[ux] make dns-conf help sentence obvious that it's a sample conf

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