change MsgHandlerError

examples/smartreceive_example.rs

@@ -1,7 +1,6 @@
 use msghandler::{smartreceive, SmartreceiveOptions};
 
-#[tokio::main]
-async fn main() {
+fn main() {
     // Simulated message JSON (received via any transport)
     let msg_json_str = r#"{
         "correlation_id": "abc123-def456-ghi789",
@@ -43,7 +42,7 @@ async fn main() {
 
     let options = SmartreceiveOptions::default();
 
-    match smartreceive(msg_json_str, &options).await {
+    match smartreceive(msg_json_str, &options) {
         Ok(envelope) => {
             println!("=== Envelope Received ===");
             println!("Correlation ID: {}", envelope.correlation_id);