add sqs clear warning

Author: paras-malhotra

queues.md

@@ -1235,7 +1235,7 @@ You may also provide the `connection` argument and `queue` option to delete jobs
 
     php artisan queue:clear redis --queue=emails
 
-> {note} Clearing jobs from queues is only available for the Redis, SQS and Database queue drivers.
+> {note} Clearing jobs from queues is only available for the Redis, SQS and Database queue drivers. The SQS message deletion process takes upto 60 seconds, so jobs sent to the SQS queue upto 60 seconds after you clear the queue might also be deleted.
 
 <a name="job-events"></a>
 ## Job Events