please, add dependency for cryptsetup in task-desktop package

[Àlex <alex@probeta.net>]

Hello,

Excuse my poor English,

Thank you for your work in Debian.

I just write this message to say that when users need to work with a
encrypted usb memory in Debian, they have to install cryptsetup by hand.
Otherwise the desktop recognizes the usb memory and even ask for a
password, but can't open the usb memory.

I think that nowadays any desktop should recognize and open encrypted
usbs memories. Distributions based in Debian like Ubuntu and Mint work
with encrypted usb memories because they have cryptsetup already installed.

Love


   Alex