Merge branch 'rails5-fix-notification-service' into 'master'

Rails 5 fix product array method delagation by manually calling .to_a in NotificationService

See merge request gitlab-org/gitlab-ee!6753

ee/app/services/ee/notification_service.rb

@@ -49,7 +49,7 @@ module EE
         recipients = project.group.members.active_without_invites_and_requests.owners_and_masters
       end
 
-      recipients.product(alerts).each do |recipient, alert|
+      recipients.to_a.product(alerts).each do |recipient, alert|
         mailer.prometheus_alert_fired_email(project.id, recipient.user.id, alert).deliver_later
       end
     end

ee/changelogs/unreleased/rails5-fix-notification-service.yml

+---
+title: Rails 5 fix product array method delagation by manually calling .to_a in NotificationService
+merge_request: 6753
+author: Jasper Maes
+type: fixed