package/nbd: bump version

nbd uses fork and threads, so remove the comment about the dependency:
it is not inherited from glib2 anymore (it has not been for a while in
fact).

The dependency on wchar is also a requirement for nbd, because configure
needs wchar to test for C99.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>