processMisReplicatedBlock incorrectly identifies under-construction blocks as under-replicated

When the NN processes mis-replicated blocks while exiting safemode, it considers under-construction blocks as under-replicated, inserting them into the neededReplicationsQueue. This makes them show up as corrupt in the metrics and UI momentarily, until they're pulled off the queue. At that point, it realizes that they aren't in fact under-replicated, correctly. This affects both the HA branch and trunk/23, best I can tell.