Fix fast last empty cache handling in 1.3

Author: Caideyipi

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/protocol/thrift/impl/ClientRPCServiceImpl.java

@@ -1008,7 +1008,8 @@ public TSExecuteStatementResp executeFastLastDataQueryForOneDeviceV2(
             if (timeValuePair == null) {
               allCached = false;
               break;
-            } else if (timeValuePair.getValue() == null) {
+            } else if (timeValuePair == DeviceLastCache.EMPTY_TIME_VALUE_PAIR
+                || timeValuePair.getValue() == null) {
               // there is no data for this sensor
               if (!canUseNullEntry) {
                 allCached = false;