Revert peer DB changes from #2724 (#2828)

## Proposed Changes

This reverts commit 53562010ec from PR #2724

Hopefully this will restore the reliability of the sync simulator.

beacon_node/network/src/service.rs

@@ -17,7 +17,7 @@ use lighthouse_network::{
     types::{GossipEncoding, GossipTopic},
     BehaviourEvent, MessageId, NetworkGlobals, PeerId,
 };
-use lighthouse_network::{MessageAcceptance, Service as LibP2PService, SyncStatus};
+use lighthouse_network::{MessageAcceptance, Service as LibP2PService};
 use slog::{crit, debug, error, info, o, trace, warn};
 use std::{net::SocketAddr, pin::Pin, sync::Arc, time::Duration};
 use store::HotColdDB;
@@ -100,10 +100,6 @@ pub enum NetworkMessage<T: EthSpec> {
         reason: GoodbyeReason,
         source: ReportSource,
     },
-    UpdatePeerSyncStatus {
-        peer_id: PeerId,
-        sync_status: SyncStatus,
-    },
 }
 
 /// Service that handles communication between internal services and the `lighthouse_network` network service.
@@ -531,9 +527,6 @@ fn spawn_service<T: BeaconChainTypes>(
                                 );
                             }
                         }
-                        NetworkMessage::UpdatePeerSyncStatus{peer_id, sync_status} => {
-                            service.libp2p.swarm.behaviour_mut().update_peers_sync_status(&peer_id, sync_status);
-                        }
                     }
                 }
                 // process any attestation service events