fix(iroh): increase buffer size for rpc controller

iroh/src/node/builder.rs

@@ -494,7 +494,7 @@ where
         .await?;
 
         // Initialize the internal RPC connection.
-        let (internal_rpc, controller) = quic_rpc::transport::flume::connection(1);
+        let (internal_rpc, controller) = quic_rpc::transport::flume::connection(32);
         // box the controller. Boxing has a special case for the flume channel that avoids allocations,
         // so this has zero overhead.
         let controller = quic_rpc::transport::boxed::Connection::new(controller);