when look up address, record transactionServiceGroup

Author: laywin

discovery/seata-discovery-nacos/src/main/java/org/apache/seata/discovery/registry/nacos/NacosRegistryServiceImpl.java

@@ -147,6 +147,7 @@ public void unsubscribe(String cluster, EventListener listener) throws Exception
 
     @Override
     public List<InetSocketAddress> lookup(String key) throws Exception {
+        transactionServiceGroup = key;
         String clusterName = getServiceGroup(key);
         if (clusterName == null) {
             String missingDataId = PREFIX_SERVICE_ROOT + CONFIG_SPLIT_CHAR + PREFIX_SERVICE_MAPPING + key;