[ISSUE #718]fix: registers a null consumerBuilder for RocketMQClientTemplate

diff --git a/rocketmq-v5-client-spring-boot/src/main/java/org/apache/rocketmq/client/autoconfigure/ExtConsumerResetConfiguration.java b/rocketmq-v5-client-spring-boot/src/main/java/org/apache/rocketmq/client/autoconfigure/ExtConsumerResetConfiguration.java
index 35837c6..8f65b40 100644
--- a/rocketmq-v5-client-spring-boot/src/main/java/org/apache/rocketmq/client/autoconfigure/ExtConsumerResetConfiguration.java
+++ b/rocketmq-v5-client-spring-boot/src/main/java/org/apache/rocketmq/client/autoconfigure/ExtConsumerResetConfiguration.java
@@ -96,8 +96,9 @@
 
         try {
             final ClientServiceProvider provider = ClientServiceProvider.loadService();
-            SimpleConsumerBuilder simpleConsumerBuilder = provider.newSimpleConsumerBuilder();
-            simpleConsumerInfo = createConsumer(annotation, simpleConsumerBuilder);
+            consumerBuilder = provider.newSimpleConsumerBuilder();
+            simpleConsumerInfo = createConsumer(annotation, consumerBuilder);
+            simpleConsumer = consumerBuilder.build();
         } catch (Exception e) {
             log.error("Failed to startup SimpleConsumer for RocketMQTemplate {}", beanName, e);
         }