Fix unused variable warning in test

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/full_integration_test.rs

@@ -235,7 +235,7 @@ async fn test_csv_created_client() {
     // Initialize CSV
     btest_rs::csv_output::init(&csv_path).unwrap();
 
-    let (tx, rx, lost, intervals) = run_client_test(
+    let (tx, rx, lost, _intervals) = run_client_test(
         "127.0.0.1", port, false, true, false, None, None,
     ).await;