Update for V4 syntax.

doc/sphinx/users-guide/vcl-example-acls.rst

@@ -15,20 +15,10 @@ the IP address of the client against an ACL with the match operator.::
   sub vcl_recv {
     if (req.method == "PURGE") {
       if (client.ip ~ local) {
-         return(lookup);
+         return(purge);
+      } else {
+         return(synth(403, "Access denied."));
       }
     } 
   }
   
-  sub vcl_hit {
-     if (req.method == "PURGE") {
-       set obj.ttl = 0s;
-       error 200 "Purged.";
-      }
-  }
-
-  sub vcl_miss {
-    if (req.method == "PURGE") {
-      error 404 "Not in cache.";
-    }
-  }