-S "stale" CLI command broken

using the "stale" time -S parameter spits the following errors:
user1@DESKTOP-1234:~$ adsbcot -U udp:127.0.0.1:4242 -S 25 -D http://192.168.0.146:8080/data/aircraft.json -I 2
------------------------------------------------------------------------
! Warining: pyrtlsdr not installed (required for using RTL-SDR devices)
------------------------------------------------------------------------
2021-05-02 20:29:03,085 pytak INFO - Running ADSBWorker with URL 'http://192.168.0.146:8080/data/aircraft.json'
2021-05-02 20:29:03,087 pytak INFO - Running EventReceiver
2021-05-02 20:29:03,088 pytak INFO - Running EventTransmitter
Task completed: <Task finished coro=<ADSBWorker.run() done, defined at /home/user1/.local/lib/python3.7/site-packages/adsbcot/classes.py:86> exception=TypeError('unsupported type for timedelta seconds component: str')>
Task exception was never retrieved
future: <Task finished coro=<ADSBWorker.run() done, defined at /home/user1/.local/lib/python3.7/site-packages/adsbcot/classes.py:86> exception=TypeError('unsupported type for timedelta seconds component: str')>
Traceback (most recent call last):
  File "/home/user1/.local/lib/python3.7/site-packages/adsbcot/classes.py", line 92, in run
    await self._get_dump1090_feed()
  File "/home/user1/.local/lib/python3.7/site-packages/adsbcot/classes.py", line 84, in _get_dump1090_feed
    await self.handle_message(aircraft)
  File "/home/user1/.local/lib/python3.7/site-packages/adsbcot/classes.py", line 57, in handle_message
    event = adsbcot.adsb_to_cot(craft, stale=self.cot_stale)
  File "/home/user1/.local/lib/python3.7/site-packages/adsbcot/functions.py", line 103, in adsb_to_cot
    event.stale = time + datetime.timedelta(seconds=stale)
TypeError: unsupported type for timedelta seconds component: str
snstac / adsbcot

-S "stale" CLI command broken #8
