Bug fix: mandos-client needs GnuPG but lacked a dependency on it. The
Mandos server, on the other hand, did not need GnuPG but declared an
incorrect dependency on it.
* debian/control (Package: mandos/Depends): Removed "gnupg (< 2)".
(Package: mandos-client/Depends): Added "gnupg (<< 2)".