AMBARI-11083. Upgrade 1.6.1 -> 2.0.1 - nagios not removed.

ambari-server/src/main/java/org/apache/ambari/server/upgrade/UpgradeCatalog200.java

@@ -467,6 +467,7 @@ public class UpgradeCatalog200 extends AbstractUpgradeCatalog {
         desiredStateDao.remove(serviceDesiredState);
 
         // remove service
+        cluster.getClusterServiceEntities().remove(nagios);
         ClusterServiceEntityPK primaryKey = new ClusterServiceEntityPK();
         primaryKey.setClusterId(nagios.getClusterId());
         primaryKey.setServiceName(nagios.getServiceName());