fix cache invalidate when deleting a groupId

git-svn-id: https://svn.apache.org/repos/asf/archiva/trunk@1583868 13f79535-47bb-0310-9956-ffa450edef68

archiva-modules/archiva-web/archiva-rest/archiva-rest-services/src/main/java/org/apache/archiva/rest/services/DefaultRepositoriesService.java

@@ -991,6 +991,7 @@ public class DefaultRepositoriesService
             // just invalidate cache entry
             String cacheKey = repositoryId + "-" + groupId;
             namespacesCache.remove( cacheKey );
+            namespacesCache.remove( repositoryId );
 
             metadataRepository.save();
         }