Actions don't restart after an AsyncCancelled

[mavnn]

If a file change triggers a longer task, and an other file is changed sos interrupts the current task with an AsyncCancelled message.

I'd then expect it to immediately restart the relevant actions, as a watch file has changed. Instead, it waits until an other change is made, and then restarts.

I'm not sure if this is by design or a bug, but either way it would be nice to have the option to restart immediately after cancellation.

If this is a bug, it might be related to #38.