Update tests/async_codec.rs

Co-authored-by: João Antônio Cardoso <[email protected]>

tests/async_codec.rs

@@ -100,7 +100,7 @@ async fn run_ping_test() -> Result<(), Box<dyn std::error::Error>> {
                 println!("{:?}", answer)
             }
             Ok(_) => {
-                panic!("Unexpected package")
+                panic!("Unexpected package. {:#?}", &item)
             }
             Err(e) => {
                 panic!("Error on decoder: {:?}", e)