Enable underscore in headers in nginx config

Signed-off-by: Lucjan Bryndza <l.bryndza@samsung.com>
Issue-ID: PORTAL-806
Change-Id: I9bd2cc1f01a13d198d705affe3cc56be96dd5ce0
diff --git a/kubernetes/contrib/ingress-nginx-post-inst/nginx_ingress_cluster_config.yaml b/kubernetes/contrib/ingress-nginx-post-inst/nginx_ingress_cluster_config.yaml
index 937828a..af0f59b 100644
--- a/kubernetes/contrib/ingress-nginx-post-inst/nginx_ingress_cluster_config.yaml
+++ b/kubernetes/contrib/ingress-nginx-post-inst/nginx_ingress_cluster_config.yaml
@@ -10,6 +10,8 @@
 
 kind: ConfigMap
 apiVersion: v1
+data:
+  enable-underscores-in-headers: "on"
 metadata:
   name: nginx-configuration
   namespace: ingress-nginx