We used to only set it for single-use offers (where it's required), but it's still interesting for multi-use offers, so let's keep it there. We also put this field in the documentation. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I noticed that offer(7) referred to `deloffer` which doesn't exist. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>