reprovide: wait a minute before reproviding

Many times, a node will start up only to shut down immediately.
In these cases, reproviding is costly to both the node, and the
rest of the network. Also note: the probability of a node being
up another minute increases with uptime.

TODO: maybe this should be 5 * time.Minute

indirect.go

@@ -32,7 +32,7 @@ func loadIndirPin(d ds.Datastore, k ds.Key) (*indirectPin, error) {
 		keys = append(keys, k)
 		refcnt[k] = v
 	}
-	log.Debugf("indirPin keys: %#v", keys)
+	// log.Debugf("indirPin keys: %#v", keys)
 
 	return &indirectPin{blockset: set.SimpleSetFromKeys(keys), refCounts: refcnt}, nil
 }