lnrpc: expose PINNED_SYNC for listpeers

lnrpc/rpc.proto

@@ -1487,6 +1487,11 @@ message Peer {
         Denotes that we are not receiving new graph updates from the peer.
         */
         PASSIVE_SYNC = 2;
+
+        /*
+        Denotes that this peer is pinned into an active sync.
+        */
+        PINNED_SYNC = 3;
     }
 
     // The type of sync we are currently performing with this peer.

lnrpc/rpc.swagger.json

@@ -2269,10 +2269,11 @@
       "enum": [
         "UNKNOWN_SYNC",
         "ACTIVE_SYNC",
-        "PASSIVE_SYNC"
+        "PASSIVE_SYNC",
+        "PINNED_SYNC"
       ],
       "default": "UNKNOWN_SYNC",
-      "description": " - UNKNOWN_SYNC: Denotes that we cannot determine the peer's current sync type.\n - ACTIVE_SYNC: Denotes that we are actively receiving new graph updates from the peer.\n - PASSIVE_SYNC: Denotes that we are not receiving new graph updates from the peer."
+      "description": " - UNKNOWN_SYNC: Denotes that we cannot determine the peer's current sync type.\n - ACTIVE_SYNC: Denotes that we are actively receiving new graph updates from the peer.\n - PASSIVE_SYNC: Denotes that we are not receiving new graph updates from the peer.\n - PINNED_SYNC: Denotes that this peer is pinned into an active sync."
     },
     "PendingChannelsResponseClosedChannel": {
       "type": "object",

rpcserver.go

@@ -2744,6 +2744,8 @@ func (r *rpcServer) ListPeers(ctx context.Context,
 				lnrpcSyncType = lnrpc.Peer_ACTIVE_SYNC
 			case discovery.PassiveSync:
 				lnrpcSyncType = lnrpc.Peer_PASSIVE_SYNC
+			case discovery.PinnedSync:
+				lnrpcSyncType = lnrpc.Peer_PINNED_SYNC
 			default:
 				return nil, fmt.Errorf("unhandled sync type %v",
 					syncType)