update /etc/hosts and system level

Change-Id: If14e63ad26c5a3fc915680c8e3569dfba526297a
diff --git a/classes/cluster/virtual-mcp-ocata-cicd/openstack/init.yml b/classes/cluster/virtual-mcp-ocata-cicd/openstack/init.yml
index 3cda036..b21c692 100644
--- a/classes/cluster/virtual-mcp-ocata-cicd/openstack/init.yml
+++ b/classes/cluster/virtual-mcp-ocata-cicd/openstack/init.yml
@@ -131,6 +131,7 @@
 
   linux:
     network:
+      purge_hosts: true
       host:
         prx:
           address: ${_param:openstack_proxy_address}