Extract EE-specific lines to EE::Gitlab::Auth::Saml::Config

Signed-off-by: Rémy Coutable <remy@rymai.me>

ee/lib/ee/gitlab/auth/saml/config.rb

+module EE
+  module Gitlab
+    module Auth
+      module Saml
+        module Config
+          extend ActiveSupport::Concern
+
+          class_methods do
+            def required_groups
+              Array(options[:required_groups])
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/auth/saml/config.rb

@@ -2,6 +2,8 @@ module Gitlab
   module Auth
     module Saml
       class Config
+        prepend ::EE::Gitlab::Auth::Saml::Config
+
         class << self
           def options
             Gitlab::Auth::OAuth::Provider.config_for('saml')
@@ -15,10 +17,6 @@ module Gitlab
             options[:external_groups]
           end
 
-          def required_groups
-            Array(options[:required_groups])
-          end
-
           def admin_groups
             options[:admin_groups]
           end