buildroot

netsniff-ng: bump to version 0.6.4

Drop patches merged upstream.

Cc: Joris Lijssens <joris.lijssens@gmail.com>
Cc: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>