[improve][broker] Print recoverBucketSnapshot log if cursorProperties are empty (#21651)

diff --git a/pulsar-broker/src/main/java/org/apache/pulsar/broker/delayed/bucket/BucketDelayedDeliveryTracker.java b/pulsar-broker/src/main/java/org/apache/pulsar/broker/delayed/bucket/BucketDelayedDeliveryTracker.java
index d7a3e80..f98c9e0 100644
--- a/pulsar-broker/src/main/java/org/apache/pulsar/broker/delayed/bucket/BucketDelayedDeliveryTracker.java
+++ b/pulsar-broker/src/main/java/org/apache/pulsar/broker/delayed/bucket/BucketDelayedDeliveryTracker.java
@@ -140,6 +140,8 @@
         ManagedCursor cursor = this.lastMutableBucket.getCursor();
         Map<String, String> cursorProperties = cursor.getCursorProperties();
         if (MapUtils.isEmpty(cursorProperties)) {
+            log.info("[{}] Recover delayed message index bucket snapshot finish, don't find bucket snapshot",
+                    dispatcher.getName());
             return 0;
         }
         FutureUtil.Sequencer<Void> sequencer = this.lastMutableBucket.getSequencer();