needless S3AFileSystem.setOptionalPutRequestParameters in S3ABlockOutputStream putObject()

There's a call to S3AFileSystem.setOptionalPutRequestParameters() in {{ S3ABlockOutputStream putObject()}}

The put request has already been created by the FS; this call is only superflous and potentially confusing.

Proposed: cut it, make the setOptionalPutRequestParameters() method private.