BC fix - no user found should still direct to a default image

plugins/unl_avatars/start.php

@@ -20,7 +20,7 @@ function unl_avatars_pg_handler($segments) {
     $size = $segments[2];
     
     if (!$user = get_user_by_username($username)) {
-        return false;
+        forward(elgg_get_simplecache_url("icons/user/default{$size}.gif"));
     }
     
     //Forward to the new guy