message: fix(api): force nmcli to actively check for connectivity
  On buildroot, nmcli networking connectivity always returns unknown, probably
  because of a file caching issue on a read-only rootfs. Changing the call to
  nmcli networking connectivity check avoids the cache.
  Closes
diff: @@ -292,7 +292,7 @@ async def available_ssids() -> List[Dict[str, Any]]:
  async def is_connected() -> str:
  """ Return nmcli's connection measure: none/portal/limited/full/unknown"""
  - res, _ = await _call(['networking', 'connectivity'])
  + res, _ = await _call(['networking', 'connectivity', 'check'])
  return res
  