lnwallet: add height hint cache to backend tests

lnwallet/interface_test.go

@@ -2068,7 +2068,19 @@ func TestLightningWallet(t *testing.T) {
 
 	rpcConfig := miningNode.RPCConfig()
 
-	chainNotifier, err := btcdnotify.New(&rpcConfig)
+	tempDir, err := ioutil.TempDir("", "channeldb")
+	if err != nil {
+		t.Fatalf("unable to create temp dir: %v", err)
+	}
+	db, err := channeldb.Open(tempDir)
+	if err != nil {
+		t.Fatalf("unable to create db: %v", err)
+	}
+	hintCache, err := chainntnfs.NewHeightHintCache(db)
+	if err != nil {
+		t.Fatalf("unable to create height hint cache: %v", err)
+	}
+	chainNotifier, err := btcdnotify.New(&rpcConfig, hintCache, hintCache)
 	if err != nil {
 		t.Fatalf("unable to create notifier: %v", err)
 	}