chainntnfs/btcdnotify: add chainParams parameter to btcdnotify.New

In this commit, we add the current chain parameters to the BtcdNotifier.
This will be used in a future commit in order to convert outputs scripts
into addresses. This is needed since the btcd backend uses these
addresses to detect whether the script encoded within it was spent by a
transaction in the chain.

chainntnfs/btcdnotify/btcd_test.go

@@ -37,7 +37,7 @@ func setUpNotifier(t *testing.T, h *rpctest.Harness) *BtcdNotifier {
 	hintCache := initHintCache(t)
 
 	rpcCfg := h.RPCConfig()
-	notifier, err := New(&rpcCfg, hintCache, hintCache)
+	notifier, err := New(&rpcCfg, chainntnfs.NetParams, hintCache, hintCache)
 	if err != nil {
 		t.Fatalf("unable to create notifier: %v", err)
 	}