Fix syntax error from last build

core/DataAccess/ArchiveWriter.php

@@ -108,7 +108,7 @@ class ArchiveWriter
         try { // TODO: this is temporary, remove when deadlocking issue is fixed
             $db->exec($insertSql);
         } catch (Exception $ex) {
-            if (\Zend_Registry::get('db')->isErrNo($e, 1213)) {
+            if (\Zend_Registry::get('db')->isErrNo($ex, 1213)) {
                 $deadlockInfo = \Piwik\Db::fetchAll("SHOW ENGINE INNODB STATUS");
                 Piwik::log("DEADLOCK INFO: " . print_r($deadlockInfo));
             }
@@ -268,4 +268,4 @@ class ArchiveWriter
     {
         return ($value === '0' || $value === false || $value === 0 || $value === 0.0);
     }
-}
+}
\ No newline at end of file