Fix the situation when transport may send data from upper levels BEFO…

…RE sending the open_ack

io/zenoh-transport/src/unicast/establishment/accept.rs

@@ -628,18 +628,19 @@ pub(crate) async fn accept_link(link: &LinkUnicast, manager: &TransportManager)
         is_lowlatency: state.ext_lowlatency.is_lowlatency(),
     };
 
-    let transport = step!(
-        manager
-            .init_transport_unicast(config, link.clone(), LinkUnicastDirection::Inbound)
-            .await
-    );
-
     // Send the open_ack on the link
     step!(link
         .send(&oack_out.open_ack.into())
         .await
         .map_err(|e| (e, Some(close::reason::GENERIC))));
 
+    // init the transport
+    let transport = step!(
+        manager
+            .init_transport_unicast(config, link.clone(), LinkUnicastDirection::Inbound)
+            .await
+    );
+
     // Sync the RX sequence number
     let _ = step!(transport
         .get_inner()