Fetch announcement in case it is not present but requested

This will make sure that if a user retries an operation, the
announcement is there.

daemon/src/oracle.rs

@@ -224,13 +224,20 @@ impl xtra::Handler<GetAnnouncement> for Actor {
         msg: GetAnnouncement,
         _ctx: &mut xtra::Context<Self>,
     ) -> Option<Announcement> {
+        let announcement =
             self.announcements
                 .get_key_value(&msg.0)
                 .map(|(id, (time, nonce_pks))| Announcement {
                     id: *id,
                     expected_outcome_time: *time,
                     nonce_pks: nonce_pks.clone(),
-            })
+                });
+
+        if announcement.is_none() {
+            self.pending_announcements.insert(msg.0);
+        }
+
+        announcement
     }
 }