[mythtvnz] Freeview channel changes

[Stephen Worthington]

I just ran my script to scan the DVB-T channels available from Wharite
and there have been some changes since my last scan on 6-Jun-2021.

These channels have gone and been replaced by placeholder channels (no
name but otherwise the same tuning data):

Apna Television
TVSN Shopping
TV29

And the "Kordia TV" channel has been renamed to "CH200".

So I have added a new line to my mhegepgsnoop channel map:

CH200	kordiatv.freeviewnz.tv

so that channel will continue to get EPG if there is any.  But I am
going to wait a bit before deleting the channels that have gone or
renaming Kordia TV in MythTV, since Apna Television and TV29 are still
listed on http://freeviewnz.tv as valid channels.