Slightly improve database driver chack

Aleksander Machniak

2013-01-31 41db2bf47db6df8b6065986b7488f3fc538ebc14

 program/lib/Roundcube/rcube_storage.php

@@ -53,6 +53,7 @@
    protected $all_headers = array(
        'IN-REPLY-TO',
        'BCC',
        'SENDER',
        'MESSAGE-ID',
        'CONTENT-TRANSFER-ENCODING',
        'REFERENCES',