Tweak node selector to be consistent with other CDN charts

Change-Id: I207f2e125c141878ce54e58c11f8d38450492678
diff --git a/mcord/mcord-cdn-local-free/values.yaml b/mcord/mcord-cdn-local-free/values.yaml
index 271f25b..863c21d 100644
--- a/mcord/mcord-cdn-local-free/values.yaml
+++ b/mcord/mcord-cdn-local-free/values.yaml
@@ -15,7 +15,7 @@
 
 namespace: epc
 nginx_hostname: "nginx"
-node_selector: "node3"
+cdn_node_selector: "node3"
 spgwu_sgiip: 13.0.0.83
 ue_ip_subnet1: 16.0.0.0/8
 ue_ip_subnet2: 17.0.0.0/8