Transition uses of `do_send` to `send`

`do_send` on `MessageChannel` suffers from the same problems as
`Address#do_send` and `Address#do_send_async`.

Our uses only send messages that never fail so we don't need to adjust
anything.

daemon/src/fan_out.rs

@@ -22,11 +22,10 @@ where
 {
     async fn handle(&mut self, message: M, _: &mut xtra::Context<Self>) {
         for receiver in &self.receivers {
-            // Not sure why here is no `do_send_async` ...
-            if receiver.do_send(message.clone()).is_err() {
-                tracing::error!(
-                    "Fan out actor was unable to send to other actor - we should never see this."
-                )
+            if receiver.send(message.clone()).await.is_err() {
+                // Should ideally remove from list but that is unnecessarily hard with Rust
+                // iterators
+                tracing::error!("Actor disconnected, cannot send message");
             }
         }
     }

daemon/src/taker_cfd.rs

@@ -167,7 +167,8 @@ impl<O, M, W> Actor<O, M, W> {
         self.order_feed_actor_inbox.send(None)?;
 
         self.send_to_maker
-            .do_send(wire::TakerToMaker::TakeOrder { order_id, quantity })?;
+            .send(wire::TakerToMaker::TakeOrder { order_id, quantity })
+            .await?;
 
         Ok(())
     }
@@ -221,13 +222,14 @@ where
         self.send_pending_update_proposals()?;
 
         self.send_to_maker
-            .do_send(wire::TakerToMaker::ProposeSettlement {
+            .send(wire::TakerToMaker::ProposeSettlement {
                 order_id: proposal.order_id,
                 timestamp: proposal.timestamp,
                 taker: proposal.taker,
                 maker: proposal.maker,
                 price: proposal.price,
-            })?;
+            })
+            .await?;
         Ok(())
     }
 
@@ -381,10 +383,11 @@ where
         self.send_pending_update_proposals()?;
 
         self.send_to_maker
-            .do_send(wire::TakerToMaker::ProposeRollOver {
+            .send(wire::TakerToMaker::ProposeRollOver {
                 order_id: proposal.order_id,
                 timestamp: proposal.timestamp,
-            })?;
+            })
+            .await?;
         Ok(())
     }
 }
@@ -667,10 +670,11 @@ where
         let (tx, sig_taker) = dlc.close_transaction(proposal)?;
 
         self.send_to_maker
-            .do_send(wire::TakerToMaker::InitiateSettlement {
+            .send(wire::TakerToMaker::InitiateSettlement {
                 order_id,
                 sig_taker,
-            })?;
+            })
+            .await?;
 
         cfd.handle(CfdStateChangeEvent::ProposalSigned(
             CollaborativeSettlement::new(