Noted by Baptiste Jonglez.

Thanks to Dave Taht and Julien Cristau for pointing out the issue.

It's been broken for ages, nobody noticed.

This allows using telnet on the local interface.

It's not like it's run that often, but I've got OCD.

This is sometimes useful after a mobility event, but it increases the
amount of control traffic when a route is unstable.  Let the periodic
update take care of mobility.