chore: log learner joins

src/protobuf.rs

@@ -36,6 +36,7 @@ impl DcacheService for MyDcacheImpl {
         let node = BasicNode {
             addr: req.addr.clone(),
         };
+        println!("Learner added: {:?}", &req.addr);
         let res = self.app.raft.add_learner(node_id, node, true).await;
         Ok(Response::new(res.into()))
     }