core: Luci openwrt 'net.arptable', 'Method not found. 0.97

Home Assistant release with the issue:

arch	x86_64
dev	false
docker	true
hassio	true
os_name	Linux
python_version	3.7.4
timezone	Europe/Amsterdam
version	0.97.0
virtualenv	false

Last working Home Assistant release (if known):

0.96.5

Operating environment (Hass.io/Docker/Windows/etc.):

Component/platform:

I get the error:

openwrt_luci_rpc.exceptions.LuciRpcMethodNotFoundError: ("method: '%s' returned an error '%s' (code: '%s).", 'net.arptable', 'Method not found.', -32601)

after i have upgraded to 0.97, before there was no issue (0.96.5). Device tracker is not working

Complete error:

Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/device_tracker/setup.py", line 164, in async_device_tracker_scan
    found_devices = await scanner.async_scan_devices()
  File "/usr/local/lib/python3.7/concurrent/futures/thread.py", line 57, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/src/homeassistant/homeassistant/components/luci/device_tracker.py", line 54, in scan_devices
    self._update_info()
  File "/usr/src/homeassistant/homeassistant/components/luci/device_tracker.py", line 82, in _update_info
    result = self.router.get_all_connected_devices(only_reachable=True)
  File "/usr/local/lib/python3.7/site-packages/openwrt_luci_rpc/__init__.py", line 39, in get_all_connected_devices
    only_reachable=only_reachable, wlan_interfaces=wlan_interfaces)
  File "/usr/local/lib/python3.7/site-packages/openwrt_luci_rpc/openwrt_luci_rpc.py", line 148, in get_all_connected_devices
    arp_result = self._call_json_rpc(*self.arp_call)
  File "/usr/local/lib/python3.7/site-packages/openwrt_luci_rpc/openwrt_luci_rpc.py", line 214, in _call_json_rpc
    method, error_message, error_code)
openwrt_luci_rpc.exceptions.LuciRpcMethodNotFoundError: ("method: '%s' returned an error '%s' (code: '%s).", 'net.arptable', 'Method not found.', -32601)