[ISSUE #9605] Fixed a potential resource leak (#9606)

Author: yx9o

broker/src/main/java/org/apache/rocketmq/broker/BrokerController.java

@@ -1539,6 +1539,10 @@ protected void shutdownBasicService() {
         if (this.transactionalMessageCheckService != null) {
             this.transactionalMessageCheckService.shutdown(false);
         }
+        
+        if (this.loadBalanceExecutor != null) {
+            this.loadBalanceExecutor.shutdown();
+        }
 
         if (this.endTransactionExecutor != null) {
             this.endTransactionExecutor.shutdown();