Shelly Plug S undocumented commands

Update Firmware:

http://<ip-shelly-plug-s>/ota?url=http://repo.shelly.cloud/firmware/rc/SHPLG-S.zip

http://<ip-shelly-plug-s>/ota?update=true

Turn on/off:‌‌

http://<ip-shelly-plug-s>/relay/0/?turn=on

http://<ip-shelly-plug-s>/relay/0/?turn=off

MQTT update_period

http://192.168.0.41/settings?mqtt_update_period=60