[tz] Patch for ziguard.awk

[Neil Fuller]

I discovered that the ziguard.awk is not entirely reversible: it doesn't
switch between vanguard and rearguard data for Namibia data completely in
all cases.

Attached is a patch with some more explanation and a proposed fix. It's
bigger than strictly necessary because I tidied up the Ireland lines rather
than applying the same fix there.

Low severity / impact and probably not an issue in the normal release
workflow : I discovered it because I was stumbling around generating my own
tarballs for testing the proposed 2020b changes. That's not something I
usually do.

As always, thanks for all the work you do.

Neil.

-- 
Google UK Limited

Registered Office: 6 Pancras Square, London, N1C 4AG
Registered in England Number: 3977902
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mm.icann.org/pipermail/tz/attachments/20201007/a673c92e/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-Fix-ziguard.awk-for-Rule-lines.patch
Type: application/octet-stream
Size: 2215 bytes
Desc: not available
URL: <http://mm.icann.org/pipermail/tz/attachments/20201007/a673c92e/0001-Fix-ziguard.awk-for-Rule-lines.patch>