set AP inactive station timeout to 120 seconds

main/wifi_transport.c

@@ -322,6 +322,8 @@ static int wifi_ap_init(void)
     err = esp_wifi_start();
     if (err) return err;
 
+    esp_wifi_set_inactive_time(WIFI_IF_AP, 120);
+
     if (strlen(STA_SSID) > 0) {
         esp_wifi_connect();
         printf("WiFi: STA connecting to \"%s\"\n", STA_SSID);