`current_application_settings` belongs on `Gitlab::CurrentSettings`

The initializers including this were doing so at the top level, so every object
loaded after them had a `current_application_settings` method. However, if
someone had rack-attack enabled (which was loaded before these initializers), it
would try to load the API, and fail, because `Gitlab::CurrentSettings` didn't
have that method.

To fix this:

1. Don't include `Gitlab::CurrentSettings` at the top level. We do not need
   `Object.new.current_application_settings` to work.
2. Make `Gitlab::CurrentSettings` explicitly `extend self`, as we already use it
   like that in several places.
3. Change the initializers to use that new form.

1 files changed, 2 insertions, 0 deletions

diff --git a/app/services/users/build_service.rb b/app/services/users/build_service.rb
index ff234a3440f..6f05500adea 100644
--- a/app/services/users/build_service.rb
+++ b/app/services/users/build_service.rb
@@ -1,5 +1,7 @@
 module Users
   class BuildService < BaseService
+    include Gitlab::CurrentSettings
+
     def initialize(current_user, params = {})
       @current_user = current_user
       @params = params.dup