Unable to add SmartThings integration due to previous webhook

Hi, I am configuring a fresh installation of HA. I am a Nabu Casa subscriber and have my Samsung SmartThings hub configured in NabuCasa. Worked fine with my previous HA installation.

This time around, I forgot to sign in to NC first, and mindlessly added the SmartThings integration from the Integrations page. As soon as it showed me the webhook URL, with a warning about Nabu Casa, I realized my mistake, aborted the install and logged in to NC.

However, now my SmartThings integration is not showing up, and when I try to add the integration, it fails immediately with the messages below in the log. It appears that the previous attempt at installing the integration left some residue that is now blocking another installation attempt. Note that SmartThings does not appear on the Integrations page, so there is no way I can remove it.

Any idea of where I can go to purge the old integration and start fresh, or any other way to enable the integration?

2020-09-16 09:58:13 ERROR (MainThread) [aiohttp.server] Error handling request
Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/aiohttp/web_protocol.py", line 418, in start
    resp = await task
  File "/usr/local/lib/python3.8/site-packages/aiohttp/web_app.py", line 458, in _handle
    resp = await handler(request)
  File "/usr/local/lib/python3.8/site-packages/aiohttp/web_middlewares.py", line 119, in impl
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/real_ip.py", line 39, in real_ip_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/ban.py", line 73, in ban_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/auth.py", line 127, in auth_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/view.py", line 129, in handle
    result = await result
  File "/usr/src/homeassistant/homeassistant/components/config/config_entries.py", line 112, in post
    return await super().post(request)
  File "/usr/src/homeassistant/homeassistant/components/http/data_validator.py", line 60, in wrapper
    result = await method(view, request, *args, **kwargs)
  File "/usr/src/homeassistant/homeassistant/helpers/data_entry_flow.py", line 69, in post
    result = await self._flow_mgr.async_init(
  File "/usr/src/homeassistant/homeassistant/data_entry_flow.py", line 128, in async_init
    result = await self._async_handle_step(
  File "/usr/src/homeassistant/homeassistant/data_entry_flow.py", line 201, in _async_handle_step
    result: Dict = await getattr(flow, method)(user_input)
  File "/usr/src/homeassistant/homeassistant/components/smartthings/config_flow.py", line 67, in async_step_user
    await setup_smartapp_endpoint(self.hass)
  File "/usr/src/homeassistant/homeassistant/components/smartthings/smartapp.py", line 238, in setup_smartapp_endpoint
    cloudhook_url = await hass.components.cloud.async_create_cloudhook(
  File "/usr/src/homeassistant/homeassistant/components/cloud/__init__.py", line 135, in async_create_cloudhook
    hook = await hass.data[DOMAIN].cloudhooks.async_create(webhook_id, True)
  File "/usr/local/lib/python3.8/site-packages/hass_nabucasa/cloudhooks.py", line 35, in async_create
    raise ValueError("Hook is already enabled for the cloud.")
ValueError: Hook is already enabled for the cloud.