Skip known-failing test

When one fetches information about a GPG key, the following fields are returned:

* content
* created_at
* id
* name
* organization
* permissions
* products
* repositories
* updated_at

Note that 'organization' is returned, not 'organization_id'. This is bad
behaviour, and GPG keys therefore also suffer from the problem described in
bugzilla bug 1122267.