Satisfyer protocol keep-alive does not shut down when device disconnected

[qdot]

Describe the bug

1. Start buttplug
2. Connect a satisfyer device
3. Turn off satisfyer device

Expected behavior Device disconnects without issue

Actual behavior Device disconnects, but an error is thrown on the next loop of the satisfyer protocol keepalive task

Additional context The task runs out-of-band of the device, so it should check the connection status and exit before running.

[qdot]

This still happens in v6. Should figure out a better way to handle it.