chore(s3demo.php): Remove note about being used on demo
chore(s3demo.php): Remove note about being used on demo

Because it is not used on the demo.
paul-herrmann/server-examples,FineUploader/server-examples,paul-herrmann/server-examples,paul-herrmann/server-examples,paul-herrmann/server-examples,FineUploader/server-examples,paul-herrmann/server-examples,FineUploader/server-examples,FineUploader/server-examples,paul-herrmann/server-examples,paul-herrmann/server-examples,paul-herrmann/server-examples,FineUploader/server-examples,FineUploader/server-examples,FineUploader/server-examples,FineUploader/server-examples