revert change on insertHook

hmy/downloader/beaconhelper.go

@@ -128,12 +128,10 @@ func (bh *beaconHelper) insertLastMileBlocks() (inserted int, bn uint64, err err
 			return
 		}
 		bh.logger.Info().Uint64("number", b.NumberU64()).Msg("Inserted block from beacon pub-sub")
-		// TODO: clean up insertHook since for beacon chain sync, we shouldn't broadcast crosslinks for all sync nodes.
-		// Crosslink broadcasting is a live operation related to the beacon consensus, which should only
-		// be triggered when there is a new beacon block produced.
-		//if bh.insertHook != nil {
-		//	bh.insertHook()
-		//}
+
+		if bh.insertHook != nil {
+			bh.insertHook()
+		}
 		inserted++
 		bn++
 	}