fix(pulsar-query): 修复pulsar backlog获取错误

service-pulsar-query/src/main/java/com/lanyuanxiaoyao/service/pulsar/PulsarQueryApplication.java

@@ -273,7 +273,7 @@ public class PulsarQueryApplication {
                 .build()) {
             Map<String, ? extends SubscriptionStats> subscriptions = admin.topics().getStats(topic).getSubscriptions();
             if (ObjectUtil.isNotNull(subscriptions) && subscriptions.containsKey(subscription)) {
-                return subscriptions.get(subscription).getBacklogSize();
+                return subscriptions.get(subscription).getMsgBacklog();
             }
             return -1L;
         }