Dumping Outputstream is closed more then once

[phax]

There seems to be a bug with Phase4 library DumpManager class, or at least with how it is closed.
After the incoming dumper writes content, AS4DumpManager::close() is called 3 times, which also calls StreamHelper.flush (aOS) each time to close the same stream.
It may work with the default file-based dumper because the OutputStream implementation that is used does not complain when it is flushed and closed many times.
We are using an S3OutputStream library to write to Amazon S3. That stream implementation throws an exception if you try to flush and close an already closed stream.

[phax]

This is part of the 2.1.0 release