Gracefully handle tunneled service restarting

[alextes]

When I restart the tunneled service, RLT (understandably) complains that the connection is broken, and that it cannot create a new one. Restarting the service, however, doesn't help.

Suggestions:

• retry less actively to connect to the local service (it tries ~10 / second now)
• re-establish the connection when the local service is available again