Case where cjdns is configured with ETHInerface for say eth3, wlan10, or fxp0. where

[wfleurant]

1. any configured interfaces goes down
2. any new interface is added.

Expected result: cjdns utilizes any configured interfaces.
Current result: cjdns does not re-add interfaces.

Possible fixes:

1. restart cjdroute
2. fix in wfleurant/cjdns 094c011c48598c3c
3. ubus could trigger cjdns API call to ETHInterface_new()