change auto clean up option to config

lang/chs/lang_settings.php

@@ -680,8 +680,6 @@ $lang_settings = array
 	'text_email_notification_note' => "是否允许用户在收取新短讯、评论等时候收到邮件提示。",
 	'text_users_get' => "首次升级至此等级的用户将获得",
 	'text_invitations_default' => "个邀请名额。默认",
-	'row_use_cron_trigger_cleanup' => '使用定时器进行清理',
-	'text_use_cron_trigger_cleanup_note' => '确保已经配置好定时任务',
 	'row_logging' => '运行日志路径',
 	'text_logging_note' => '请填写你的运行时日志路径',
 );

lang/cht/lang_settings.php

@@ -680,8 +680,6 @@ $lang_settings = array
 	'text_email_notification_note' => "是否允許用戶在收取新短訊、評論等時候收到郵件輔助說明。",
 	'text_users_get' => "首次升級至此等級的用戶將獲得",
 	'text_invitations_default' => "個邀請名額。預設",
-	'row_use_cron_trigger_cleanup' => '使用定時器進行清理',
-	'text_use_cron_trigger_cleanup_note' => '確保已經配置好定時任務',
 	'row_logging' => '運行日誌路徑',
 	'text_logging_note' => '請填寫妳的運行時日誌路徑',
 );

lang/en/lang_settings.php

@@ -680,8 +680,6 @@ $lang_settings = array
 	'text_email_notification_note' => "Allow users to receive email notification when he gets new pm, comment, etc.",
 	'text_users_get' => "Users would get ",
 	'text_invitations_default' => " invitations the first time he is promoted to this class. Default ",
-	'row_use_cron_trigger_cleanup' => 'Use cron trigger cleanup',
-	'text_use_cron_trigger_cleanup_note' => 'Make sure have configure crontab job',
 	'row_logging' => 'Runtime log path',
 	'text_logging_note' => 'Please enter your runtime log path',
 );