[bug] No valid IP addresses to initiate connections found

[nemesifier]

Recent versions of OpenWISP Controller can raise a ValueError exception which is not caught by this module.
When this happens, instead of continuing to retry, the retry mechanism stops, eg:

Trying to reconnect to device at 172.16.0.32 (attempt n.5)...
Device not reachable yet, (timed out).
retrying in 20 seconds...
Trying to reconnect to device at (attempt n.6)...
No valid IP addresses to initiate connections found

This looks like a bug. The system must keep retrying until the max amount of retries are reached, in that case the last line of the log would look different.