Revert "Add Session::abort_save() to Kohana."

Obsoleted by upstream fix.

This reverts commit 06f066164f.

modules/gallery/controllers/file_proxy.php

@@ -112,9 +112,6 @@ class File_Proxy_Controller extends Controller {
       kohana::show_404();
     }
 
-    // We don't need to save the session for this request
-    Session::abort_save();
-
     // Dump out the image
     header("Content-Type: $item->mime_type");
     Kohana::close_buffers(false);