Country field formatter settings form is not accessible

Problem/Motivation

"Country" field formatter defines a setting form to chose between showing country name or country code. However, form is not visible to the users making it impossible to change the setting.

Steps to reproduce

Go to field's "Manage Display" page. Select "Country" as a field formatter. You will see a summary text "Show as country name" but you won't be able to change the setting. Cogwheel icon is missing and settings form can't be accessed.