TAP dump on an empty bucket does not close connection

Create an empty bucket on a single node, and create a TAP 'dump' connection to it.

The TAP connection does not go through the ACK and conn-closing dance. Instead, the TAP connection just regularly sends NOOP messages every N seconds, keeping the conn open.

In comparison, a bucket that has items in it will stream items through the TAP dump conn, and the server will eventually, correctly, close the conn after the last ACK is received.