In commit 3828ea67 (deps: ntlmclient: fix missing htonll symbols on
FreeBSD and SunOS, 2020-02-21), we've fixed compilation on BSDs due to
missing `htonll` wrappers. While we are now using `htobe64` for both
Linux and OpenBSD, we decided to use `bswap64` on FreeBSD. While correct
on little endian systems, where we will swap from little- to big-endian,
we will also do the swap on big endian systems. As a result, we do not
use network byte order on such systems.

Fix the issue by using htobe64, as well.