Update route-server-note-nva-peering.md

Changed language from a "Recommend" to an "Ensure", failing to peer both IPs results in inconsistent behavior and the failure of routes from the NVA to be advertised to Azure, this should ensure users know it is a requirement as documented in the Q& A here: https://learn.microsoft.com/en-us/azure/route-server/route-server-faq

Author: IllegalAxis

includes/route-server-note-nva-peering.md

@@ -6,4 +6,4 @@ ms.topic: include
 ms.date: 09/16/2024
 ---
 > [!IMPORTANT]
-> We recommend peering each NVA with both route server instances to ensure that virtual network routes are advertised over the NVA connections and achieve high availability.
+> Ensure you peer the NVA with both route server instance IPs to ensure that virtual network routes are advertised over the NVA connections and achieve high availability.