unbound generating too many log messages

[Taylor R Campbell]

   Date: Tue, 19 Jan 2016 16:41:08 +0100
   From: "W.C.A. Wijngaards via Unbound-users" <unbound-users at unbound.net>

   There was already a similar for for permission denied spammed when the
   network was down.  But your system returns a different errno in that
   situation.  I have squelched the errno EADDRNOTAVAIL (Cannot assign
   requested address): it is hidden when verbosity is low, visible if you
   increase the verbosity.  That hopefully keeps Philippe's logs clean.

Thanks!  That only partially addresses the problem, though: while
unbound will no longer clutter logs as long as the network is down, it
will still eat CPU -- and it will do so silently now, unless verbose
logs are enabled.

It seems to me that it would be better if Unbound did not busy-wait
for the network to come back up, or for a change in whatever condition
is causing the spew.  However, I don't know the code well enough to
suggest any particular changes to accomplish this.