Fix array_merge-error in ML-Popup (#27)

serendipity_admin_image_selector.php

@@ -295,8 +295,7 @@ switch ($serendipity['GET']['step']) {
           ($serendipity['showMediaToolbar'] ? true : false),
           '?serendipity[step]=1' . $add_url . '&serendipity[textarea]='. htmlspecialchars($serendipity['GET']['textarea']),
           true,
-          null,
+          null
-          false
         );
 }