Fd leak in handle_files

[mseri]

There are scenarios if a client leaves before consuming the full response,
we might have a reference to a stream that doesn't get drained.

Not draining or closing the stream can lead to issues if its holding a resource like
a file handle as those resources will never be closed, leading to a leak.

Reported by Stéphane Glondu
Fix by samhot and anuragsoni in #977