Update error message in /116 pool migration note

The error message also prompts to choose a different data center, so adding that to the paragraph.

Author: andystevensname

openapi.yaml

@@ -4998,7 +4998,8 @@ paths:
         **Note:** Next Generation Network (NGN) data centers do not support IPv6 `/116` pools or IP Failover.
         If you have these features enabled on your Linode and attempt to migrate to an NGN data center,
         the migration will not initiate. NGN data centers include Toronto and Mumbai. If a Linode cannot be
-        migrated because of an incompatibility, the user will be prompted to contact support.
+        migrated because of an incompatibility, the user will be prompted to select a different data center
+        or contact support.
       tags:
        - Linode Instances
       operationId: migrateLinodeInstance