[tz] Casey time zone change

[Steffen Thorsen]

Actually I need to correct myself on one of dates:

The October 2019 change was 2 days earlier, 4 October 2019.

On 2020-10-02 09:05, Paul Eggert wrote:

> Thanks for the heads-up about Casey. Reading between the lines of your 
> message, it appears that we also need an update for Macquarie Island. 
> tzdb has Macquarie at +11 all year due to email you sent us on 
> 2010-03-10. However, that experiment lasted just one year according to 
> your records at timeanddate.com, and Macquarie has used Tasmanian 
> rules since then.
>
> Proposed patch attached. We're about to do a new release anyway 
> because of Yukon and so might as well fold this in.