typo - missed changing Unsupported to Not Supported for 3.19

Author: sujeet-kr

calico-enterprise_versioned_docs/version-3.19-2/networking/egress/egress-gateway-on-prem.mdx

@@ -159,7 +159,7 @@ patch release.
 - Calico CNI
 - Open port UDP 4790 on the host
 
-**Unsupported**
+**Not Supported**
 
 - GKE
 - Windows