When a destination is removed, its container is stopped and removed.
This preempts the ContainerWait call in the destination loop, which then
tries to call ContainerInspect to infer if the container is restarting
or not.
It was already known that this call is prone to race conditions. This
commit handles an additional case where the container has already been
completely removed by the time the call is made; we can safely infer
that it is not restarting.