message: add Connection: close header to long-poll response
diff: @@ -372,6 +372,7 @@ void JSONRPCRequest::PollStart() {
  // send an empty space to the client to ensure that it's still alive.
  assert(!isLongPolling);
  req->WriteHeader("Content-Type", "application/json");
  + req->WriteHeader("Connection", "close");
  req->Chunk(std::string(" "));
  isLongPolling = true;
  }
  