support flexihasher with more replicas (allowing for a more even distribution)

db-hash.php

 <?php
 
 require_once(dirname(__FILE__) . '/flexihash.php');
+require_once( ABSPATH . 'wp-config.php' );
 
-$wpdb->hash_map = new Flexihash();
+$wpdb->hash_map = new Flexihash(null, R2DB_FLEXIHASH_REPLICAS);
 
 /* Hashing function to map blogs to databases.
  *
@@ -16,4 +17,3 @@ function noblogs_db_callback($query, $wpdb) {
   }
 }
 $wpdb->add_callback('noblogs_db_callback');
-