Sync and multi-client updates (#1044)

* Update finalized/head sync logic

* Correct sync logging

* Handle status during sync gracefully

beacon_node/network/src/sync/range_sync/chain.rs

@@ -634,10 +634,7 @@ impl<T: BeaconChainTypes> SyncingChain<T> {
     ) -> ProcessingResult {
         batch.retries += 1;
 
-        // TODO: Handle partially downloaded batches. Update this when building a new batch
-        // processor thread.
-
-        if batch.retries > MAX_BATCH_RETRIES {
+        if batch.retries > MAX_BATCH_RETRIES || self.peer_pool.is_empty() {
             // chain is unrecoverable, remove it
             ProcessingResult::RemoveChain
         } else {