Fix class mapping for model_manager cluster

Change-Id: Id2e8fa351ecacf8d8e21e8f7453b1820a23651de
diff --git a/classes/cluster/model_manager/infra/config.yml b/classes/cluster/model_manager/infra/config.yml
index 68e743b..246ef01 100644
--- a/classes/cluster/model_manager/infra/config.yml
+++ b/classes/cluster/model_manager/infra/config.yml
@@ -74,6 +74,5 @@
           expression: <<node_hostname>>__equals__web0
           cluster_param:
             model_manager_node00_address:
-              value_template:
-                - <<node_control_ip>>
+              value_template: <<node_control_ip>>