Inconsistent database configuration (MySQL)

I just noticed that the database configuration for MySQL is inconsistent.

In https://gitlab.com/gitlab-org/gitlab-ce/blob/9-0-stable/config/database.yml.mysql it says:

production:
  adapter: mysql2
  encoding: utf8
  collation: utf8_general_ci

In https://gitlab.com/gitlab-org/gitlab-ce/blob/9-0-stable/doc/install/database_mysql.md#tables-and-data-conversion-to-utf8mb4 it says:

production:
  adapter: mysql2
  encoding: utf8mb4
  collation: utf8mb4_general_ci

Which of those configurations is the correct one?