We have the following case: server immediatelly returns error
code to client if request size more than allowed.
In this case 'onProgress' event continues to process
uploading, but 'onComplete' or 'onHTTPError' event fires with delay
in several seconds.
It seems that fileReference starts to process response from
server only after full file has been posted to server. As more file
size - then longer delay occurs.
Can somebody explain how we can immediatlly cancel uploading