hostapd: backport fix for wnm_sleep_mode=0

hostapd: backport fix for wnm_sleep_mode=0

wpa_disable_eapol_key_retries can't prevent attacks against the Wireless
Network Management (WNM) Sleep Mode handshake. Currently, hostapd
processes WNM Sleep Mode requests from clients regardless of the setting
wnm_sleep_mode. Backport Jouni Malinen's upstream patch 114f2830 in
order to ignore such requests by clients when wnm_sleep_mode is disabled
(which is the default).

Signed-off-by: Timo Sigurdsson <public_timo.s@silentcreek.de>
[rewrite commit subject (<= 50 characters), bump PKG_RELEASE]
Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>