BUILD: makefile: enable crypt(3) for OpenBSD

Allow OpenBSD to support encrypted passwords in Userlists.

OpenBSD's crypt(3) function is provided directly by libc and does not
require -lcrypt.
Signed-off-by: Matthieu Guegan <matthieu.guegan@deindeal.ch>
(cherry picked from commit 496374e59246349fe0c84af68c5490ba5b6bad33)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
1 file changed