Removed unsupported message for k8s nmstate

Author: Shubha Narayanan

modules/nw-ovn-kubernetes-matrix.adoc

@@ -24,7 +24,7 @@ ifeval::["{context}" == "about-ovn-kubernetes"]
 
 |IPsec encryption for intra-cluster communication|Supported|Not supported
 
-|IPv6|Supported ^[3]^ ^[4]^|Not supported
+|IPv6|Supported ^[3]^|Not supported
 
 |Kubernetes network policy|Supported|Supported