-added check for caching_enabled (#1485051)

alecpl

2008-05-12 fc231219823abe77a8e6b6421699a9bf99a69e48

 program/include/rcube_imap.php

@@ -1903,6 +1903,9 @@
   */
  function clear_cache($key=NULL)
    {
    if (!$this->caching_enabled)
      return;
    
    if ($key===NULL)
      {
      foreach ($this->cache as $key => $data)