Fix build failure (#504)

diff --git a/dubbo-spring-boot-samples/dubbo-registry-nacos-samples/consumer-sample/pom.xml b/dubbo-spring-boot-samples/dubbo-registry-nacos-samples/consumer-sample/pom.xml
index fd0cc79..0c1260e 100644
--- a/dubbo-spring-boot-samples/dubbo-registry-nacos-samples/consumer-sample/pom.xml
+++ b/dubbo-spring-boot-samples/dubbo-registry-nacos-samples/consumer-sample/pom.xml
@@ -21,7 +21,8 @@
     <parent>
         <artifactId>dubbo-spring-boot-registry-nacos-samples</artifactId>
         <groupId>org.apache.dubbo.samples</groupId>
-        <version>2.7.1</version>
+        <version>${revision}</version>
+        <relativePath>../pom.xml</relativePath>
     </parent>
     <modelVersion>4.0.0</modelVersion>