Try to fix overly agressive static preventing cache pages displaying, a=chris

diff --git a/src/library/WebArchiveBundle.php b/src/library/WebArchiveBundle.php
index de62ecd6e..ab1403098 100755
--- a/src/library/WebArchiveBundle.php
+++ b/src/library/WebArchiveBundle.php
@@ -216,13 +216,10 @@ class WebArchiveBundle
      */
     public function getPage($offset, $partition)
     {
-        static $file_handles;
-        if (!isset($file_handles[$partition])) {
-            $file_handles[$partition] = $this->getPartition($partition)->open();
-        }
+        $partition_handle = $this->getPartition($partition)->open();
         $page_array =
             $this->getPartition($partition)->getObjects(
-                $offset, 1, true, $file_handles[$partition]);
+                $offset, 1, true, $partition_handle);
         if (isset($page_array[0][1])) {
             return $page_array[0][1];
         } else {