Ensure device is removed from running Zino state when a router is removed from polldevs.cf

[lunkwill42]

No description provided.

[lunkwill42]

I think this may already be implemented, but we should check.

[johannaengland]

Yes, this is already take care of when loading the pollfile:

zino/src/zino/scheduler.py

Lines 63 to 64 in 41a87dc

	for device in deleted_devices:
	del state.polldevs[device]

[johannaengland]

Actually, now that I think about it further, we do remove the device from state.polldevs, but we still keep a lot of information in state.state, specifically state.state.devices and state.state.addresses and potentially state.state.flapping.

So a discussion is probably in order on how much information we want to keep about devices that have been removed from the pollfile.