Receiving notifications even though disabled

*What I did:*

For the keybasefriends group, #general channel, I checked the box "Ignore at-here and at-channel mentions", and selected "Never" for desktop and mobile notifications.

*What I expect to happen:*

My phone should not get a push notification from that channel.

*What actually happened:*

I received two push notifications when someone presumably used at-channel (the message was exploding but other comments indicate that's what happened).

*System information:*

- Android 7.0
- Keybase 2.8.0

Start with the Android 7.0 reproduction described in the issue for the keybasefriends #general channel, using the "Ignore at-here and at-channel mentions" and "Never" notification settings. Compare the settings with the two received push notifications. Done means an at-channel message produces no push notification under those settings.

Written by the indexing model from the issue text.