custom_announcement scheduler 未取得 lockfile 鎖時跳過排程，修正 NotRunningError 導致 worker 開機失敗無限重啟

custom_announcement/config/initializers/scheduler.rb

@@ -3,7 +3,9 @@ require 'rufus-scheduler'
 unless defined?(Rails::Console) || Rails.env.test? || File.split($0).last == 'rake'
   scheduler = Rufus::Scheduler.new(lockfile: Rails.root.join('tmp', 'custom_bulletin_scheduler.lock').to_s)
 
-  scheduler.cron '43 2 * * *' do
-    CustomBulletin.where(is_preview: true).destroy_all
+  if scheduler.up?
+    scheduler.cron '43 2 * * *' do
+      CustomBulletin.where(is_preview: true).destroy_all
+    end
   end
 end