Fix port

Author: guanquann

backend/code-execution-service/server.ts

@@ -1,6 +1,6 @@
 import app from "./app";
 
-const PORT = process.env.SERVICE_PORT || 3003;
+const PORT = process.env.SERVICE_PORT || 3004;
 
 if (process.env.NODE_ENV !== "test") {
   app.listen(PORT, () => {