`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, 1 insertions, 1 deletions

diff --git a/lib/gitlab/polling_interval.rb b/lib/gitlab/polling_interval.rb
index f0c50584f07..4780675a492 100644
--- a/lib/gitlab/polling_interval.rb
+++ b/lib/gitlab/polling_interval.rb
@@ -1,6 +1,6 @@
 module Gitlab
   class PollingInterval
-    include Gitlab::CurrentSettings
+    extend Gitlab::CurrentSettings
 
     HEADER_NAME = 'Poll-Interval'.freeze