UI to change country broken on Docker image

[benfrancis]

Reported in https://discourse.mozilla.org/t/webthings-gateway-2-1-beta-available-for-testing/147818/5

STR:

• Navigate to Settings -> Localisation
• Try to change country

Expected:

• Use can change the country

Actual:

• User can't change the country

All this feature actually does is set the regulatory country for the Wi-Fi adapter, which was important for the old Raspberry Pi image but likely unnecessarily when running the Docker image on your own OS. The UI looks broken so we should either make it read only (if it shows the correct regulatory country for the underlying OS), or just hide it.

[benfrancis]

Probably timezone too.