Bug: Notifications created while focused on one monitor will be created on the other, if the other monitor already contains some notifications

[zjeffer]

To reproduce

1. Create some notifications on monitor 1 with a high timeout
2. Focus on monitor 2
3. While the notifications on monitor 1 are still present, create a notification while focused on monitor 2
4. The new notification will still be created on monitor 1, while we were focused on monitor 2.

Expected behaviour

The new notification should be created on monitor 2