ar71xx: correct AVM FRITZ Repeater 450E WPS button flag

The AVM FRITZ!WLAN Repeater 450E's WPS button is not active low.

Correct the active low flag to avoid unintenional activation of
failsafe mode on boot.

Signed-off-by: David Bauer <mail@david-bauer.net>
(cherry picked from commit 1d4f2ca610)

target/linux/ar71xx/files/arch/mips/ath79/mach-fritz450e.c

@@ -115,7 +115,7 @@ static struct gpio_keys_button fritz450E_gpio_keys[] __initdata = {
 		.code			= KEY_WPS_BUTTON,
 		.debounce_interval	= FRITZ450E_KEYS_DEBOUNCE_INTERVAL,
 		.gpio			= FRITZ450E_GPIO_BTN_WPS,
-		.active_low		= 1,
+		.active_low		= 0,
 	}
 };