Update draft-ietf-tls-esni.md

Co-authored-by: Benjamin M. Schwartz <[email protected]>

draft-ietf-tls-esni.md

@@ -931,7 +931,8 @@ connection. Otherwise, it might become possible for the client to have
 the wrong public name for the server, thus making recovery impossible.
 
 ECHConfigs learned from ECH rejection can be used as a tracking
-vector. Clients SHOULD give them the same lifetime as other server-based
+vector. Clients SHOULD impose the same lifetime and scope restrictions
+that they apply to other server-based
 tracking vectors such as PSKs.
 
 In general, it is safest to try to retrieve a new ECHConfig unless