fix(logging): correct string template for server URL

Replaced incorrect curly braces in the console log statement with proper template literals to accurately display the HOST and PORT values. This ensures the tracker URL is displayed correctly in the console, improving debugging and monitoring.

tracker.js

@@ -19,7 +19,7 @@ server.on('warning', (err) => {
 });
 
 server.on('listening', () => {
-  console.log(`Tracker is listening on http://{HOST}:{PORT}`);
+  console.log(`Tracker is listening on http://${HOST}:${PORT}`);
 });
 
 server.listen(PORT);