Fix order of steps to prevent PostgreSQL errors when running migration
In the docs about upgrading 8.5 to 8.6, the step that explains PostgreSQL requirements for Gitlab 8.6 should come before the migration to prevent errors.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
In the docs about upgrading 8.5 to 8.6, the step that explains PostgreSQL requirements for Gitlab 8.6 should come before the migration to prevent errors.