Updated error messgae

src/http/handler.rs

@@ -142,7 +142,7 @@ fn endpoint_handler(
 
     let buf = match usimp::endpoint(endpoint, input) {
         Ok(output) => output.to_string() + "\r\n",
-        Err(e) => "{\"status\":\"error\"}\r\n".to_string(),
+        Err(e) => format!("{{\"status\":\"error\",\"message\":\"{}\"}}\r\n", e),
     };
 
     // TODO compress