set interfaces wireless wlan0 country-code suggests uk as a possible choice, however there's no uk in ISO 3166

This is the list it suggests: https://github.com/vyos/vyos-1x/blob/2872f386b02c5e1c6df2c10f7c84e8478fd38c41/interface-definitions/interfaces_wireless.xml.in#L458

<completionHelp>
  <list>us eu jp de uk cn es fr ru</list>
</completionHelp>

But this is the list that linux wireless' iw reg set command will accept: https://git.kernel.org/pub/scm/linux/kernel/git/wens/wireless-regdb.git/tree/db.txt#n688

There is no country UK in the linux list, the correct entry for the United Kingdom is GB

We should s/uk/gb/ on the completion list.