Servers fail to restart when control channel socket has been orphaned by a previous execution
kea-dhcp-ddns cannot be restarted,if configured for control channel and then shutdown via ctl-C. The control channel socket gets "orphaned" and as long as it exists, the server will exit with "address already in use" error. kea-dhcp4/6, behave somewhat differently. They will fail on the first restart, but not on a subsequent restart, so somewhere along the lines they are removing the socket?