[tz] Duplicated shell commands on the tz-link.html IANA page

[Max Nikulin]

Hi,

Some time ago I have noticed that shell commands are duplicated in the 
"Downloading the tz database" section on the following page
https://data.iana.org/time-zones/tz-link.html#download

> mkdir tzdb
> cd tzdb
> wget https://www.iana.org/time-zones/repository/tzcode-latest.tar.gz
> wget https://www.iana.org/time-zones/repository/tzdata-latest.tar.gz
> gzip -dc tzcode-latest.tar.gz | tar -xf -
> gzip -dc tzdata-latest.tar.gz | tar -xf -

I think it is better to remove some commands.