move println into error

src/main.rs

@@ -58,7 +58,7 @@ async fn run() -> Result<(), KuranteError> {
     }
 
     if let Err(why) = client.start().await {
-        println!("An error occurred while running the client: {:?}", why);
+        error!("An error occurred while running the client: {:?}", why);
     }
 
     Ok(())