`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, 3 insertions, 1 deletions

diff --git a/app/mailers/base_mailer.rb b/app/mailers/base_mailer.rb
index 654468bc7fe..8e99db444d6 100644
--- a/app/mailers/base_mailer.rb
+++ b/app/mailers/base_mailer.rb
@@ -1,11 +1,13 @@
 class BaseMailer < ActionMailer::Base
+  include Gitlab::CurrentSettings
+
   around_action :render_with_default_locale
 
   helper ApplicationHelper
   helper MarkupHelper
 
   attr_accessor :current_user
-  helper_method :current_user, :can?
+  helper_method :current_user, :can?, :current_application_settings
 
   default from:     proc { default_sender_address.format }
   default reply_to: proc { default_reply_to_address.format }