Does not pickup channels with three-digit channel number
I have configured channels with a three-digit channel number in my configuration, but they are not picked up as I cannot see them in the `Home` app:

```json
{
    "name": "Pro7 MAXX",
    "channel": 506,
    "source": "dvbc"
},
```

Other channels with one- or two-digit channel numbers show up fine.