Fix umlauts in Kolab share names

Horde_Imap_Client handles all mailbox names as UTF-8,
it's not a good idea to try a brute-force conversion
from modified UTF-7 to UTF-8. In fact it's just unnecessary.

Bug: 12553
Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Signed-off-by: Jan Schneider <jan@horde.org>
Proper Horde_Imap_Client dependency

Bug: 12553
Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Signed-off-by: Jan Schneider <jan@horde.org>