CVE-2016-0771: tests/dns: FORMERR can simply timeout against Windows

Two requests with identical parameters which are poorly formatted, can
non-deterministically return FORMERR or simply fail to give a response.

Setting the timeout to a number allows Windows to succeed.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11128
BUG: https://bugzilla.samba.org/show_bug.cgi?id=11686

Signed-off-by: Garming Sam <garming@catalyst.net.nz>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
