Fix the fix for empty text parts handling (#1488757)

Aleksander Machniak

2012-10-17 070b8e9f7144d3f517c68356eacdf3e96484be06

 program/include/rcube_session.php

@@ -315,7 +315,8 @@
  public function mc_destroy($key)
  {
    if ($key) {
      $this->memcache->delete($key);
      // #1488592: use 2nd argument
      $this->memcache->delete($key, 0);
    }

    return true;