fix tiny spacing issue, a=chris

diff --git a/lib/index_manager.php b/lib/index_manager.php
index 2a2ac7953..e0cbcc27a 100644
--- a/lib/index_manager.php
+++ b/lib/index_manager.php
@@ -168,7 +168,7 @@ class IndexManager implements CrawlConstants
             $pre_hash = $hash;
         }
        if(!isset(IndexManager::$dictionary[$index_name][$hash][$shift][
-            $mask][$threshold])) {
+           $mask][$threshold])) {
            $tmp = array();
            $test_mask = "";
            if(isset(IndexManager::$dictionary[$index_name][$pre_hash][