Fix for new ai3 noblogs_load_backends() signature

lib/blogs.php

@@ -33,7 +33,7 @@ function noblogs_get_backend_for_blog($blog_id) {
   // (we cannot use the map in $wpdb because it doesn't have the
   // backend array anymore).
   $hashmap = new Flexihash(null, R2DB_FLEXIHASH_REPLICAS);
-  $reversemap = noblogs_load_backends(NOBLOGS_BACKEND_CONFIG, $hashmap);
+  $reversemap = noblogs_load_backends($hashmap);
 
   // Lookup the blog ID using the $wpdb hash just to be safe (though
   // we should get an identical result using $hashmap).