Comment 7 for bug 1706147

Thanks Mike, thanks Galen. Slapping a pullrequest on this. Note the milestone may need to change.

To test:

1. Add $self->session->force_recycle(1); to an API handler.
2. Restart services and confirm which PIDs are active for the affected drone type.
3. Send a request to the modified API.
4. Confirm the one of the drone PIDs is no more and has been replaced by a new one.

Alternatively, raise logging to INTERNAL before restarting and look for a new message "server: child exiting early on force_recycle" after making the API call.