HADOOP-15821. Addendum patch to fix Hadoop Registry parent project.

              Contributed by Íñigo Goiri

hadoop-common-project/hadoop-registry/pom.xml

@@ -20,6 +20,7 @@
     <artifactId>hadoop-project</artifactId>
     <groupId>org.apache.hadoop</groupId>
     <version>3.3.0-SNAPSHOT</version>
+    <relativePath>../../hadoop-project</relativePath>
   </parent>
   <modelVersion>4.0.0</modelVersion>
   <artifactId>hadoop-registry</artifactId>