fix another notice in unpackPostings 2, a=chris

diff --git a/src/library/IndexDocumentBundle.php b/src/library/IndexDocumentBundle.php
index 4ef638ba6..b9e9bc7b9 100644
--- a/src/library/IndexDocumentBundle.php
+++ b/src/library/IndexDocumentBundle.php
@@ -1419,6 +1419,7 @@ class IndexDocumentBundle implements CrawlConstants
         for ($i = 0; $i < $num_items; $i++) {
             if (!isset($postings_string[$current_pos])) {
                 crawlLog("Posting decode error");
+                break;
             }
             $int_info = ord($postings_string[$current_pos]);
             $current_pos++;