Fix mentions in direct statuses not being delivered via AP (#4806)

app/services/process_mentions_service.rb

@@ -41,7 +41,7 @@ class ProcessMentionsService < BaseService
       NotifyService.new.call(mentioned_account, mention)
     elsif mentioned_account.ostatus? && (Rails.configuration.x.use_ostatus_privacy || !status.stream_entry.hidden?)
       NotificationWorker.perform_async(stream_entry_to_xml(status.stream_entry), status.account_id, mentioned_account.id)
-    elsif mentioned_account.activitypub? && !mentioned_account.following?(status.account)
+    elsif mentioned_account.activitypub?
       ActivityPub::DeliveryWorker.perform_async(build_json(mention.status), mention.status.account_id, mentioned_account.inbox_url)
     end
   end