Use http scheme for k8s rally

Change-Id: Iabdfa0c208eae61acb4543e831b3bcaf7469a886
Related-bug: https://mirantis.jira.com/browse/PROD-23235
diff --git a/src/com/mirantis/mcp/Validate.groovy b/src/com/mirantis/mcp/Validate.groovy
index e125f50..0dee39e 100644
--- a/src/com/mirantis/mcp/Validate.groovy
+++ b/src/com/mirantis/mcp/Validate.groovy
@@ -452,7 +452,7 @@
       def _pillar = salt.getPillar(master, 'I@kubernetes:master and *01*', 'kubernetes:master')
       def kubernetes = _pillar['return'][0].values()[0]
       env_vars = [
-          "KUBERNETES_HOST=${kubernetes.apiserver.vip_address}" +
+          "KUBERNETES_HOST=http://${kubernetes.apiserver.vip_address}" +
           ":${kubernetes.apiserver.insecure_port}",
           "KUBERNETES_CERT_AUTH=${dest_folder}/k8s-ca.crt",
           "KUBERNETES_CLIENT_KEY=${dest_folder}/k8s-client.key",