simplify leaving lobby packet sending

src/ship/packet/handler/room.rs

@@ -27,16 +27,19 @@ pub fn create_room(id: ClientId,
     let join_room = builder::room::join_room(id, clients, client_location, room_id, &room)?;
     rooms[room_id.0] = Some(room);
 
-    let leader = client_location.get_area_leader(area);
-    let result = vec![(id, SendShipPacket::JoinRoom(join_room))].into_iter();
-    match leader {
-        Ok(leader) => Ok(Box::new(result.chain(lobby_neighbors
+    let mut result: Box<dyn Iterator<Item=(ClientId, SendShipPacket)> + Send> = Box::new(
+        vec![(id, SendShipPacket::JoinRoom(join_room))].into_iter()
+    );
+    if let Ok(leader) = client_location.get_area_leader(area) {
+        let leave_lobby = SendShipPacket::LeaveLobby(LeaveLobby::new(area_client.local_client.id(), leader.local_client.id()));
+        result = Box::new(result.chain(lobby_neighbors
                                        .into_iter()
                                        .map(move |c| {
-                                                (c.client, SendShipPacket::LeaveLobby(LeaveLobby::new(area_client.local_client.id(), leader.local_client.id())))
-                                            })))),
-        Err(_) => Ok(Box::new(result))
+                                           (c.client, leave_lobby.clone())
+                                       })));
     }
+
+    Ok(result)
 }
 
 pub fn room_name_request(id: ClientId,