Fix call helmRepoIndex method

Change-Id: Ia1a4e27512f6d6a64a56b79d0fad4ba963b88f53
Related-PROD: PROD-33154
diff --git a/src/com/mirantis/mk/Helm.groovy b/src/com/mirantis/mk/Helm.groovy
index 280bf63..72d95cb 100644
--- a/src/com/mirantis/mk/Helm.groovy
+++ b/src/com/mirantis/mk/Helm.groovy
@@ -44,7 +44,7 @@
         }
         helmExtraParams += " --merge index-upstream.yaml"
     }
-    helm.helmRepoIndex(helmExtraParams, helmRepoDir)
+    helmRepoIndex(helmExtraParams, helmRepoDir)
 }
 
 /**