Docs: ScalaStream page shows example using deprecated ChunkedResult

http://www.playframework.com/documentation/2.3.x/ScalaStream

This page shows an example using `ChunkedResult`, which is deprecated. The migration guide for 2.2 recommends replacing these with `Ok.chunked` or manually sets proper headers and use enumeratees: http://www.playframework.com/documentation/2.3.x/Migration22.