Wait longer for inactive client probe (empty data frame)

Some devices cannot respond to inactive client probe (empty data frame)
within one second. For example, iPhone may take up to 3 secs. This
becomes a significant problem when ap_max_inactivity is set to lower
value such as 10 secs. iPhone can lose Wi-Fi connection after ~1 min
of user inactivity.

Signed-off-by: Dmitry Ivanov <dima@ubnt.com>

src/ap/sta_info.h

@@ -181,7 +181,7 @@ struct sta_info {
  * AP_DISASSOC_DELAY seconds. Similarly, the station will be deauthenticated
  * after AP_DEAUTH_DELAY seconds has passed after disassociation. */
 #define AP_MAX_INACTIVITY (5 * 60)
-#define AP_DISASSOC_DELAY (1)
+#define AP_DISASSOC_DELAY (3)
 #define AP_DEAUTH_DELAY (1)
 /* Number of seconds to keep STA entry with Authenticated flag after it has
  * been disassociated. */