Merge pull request #1478 from wpaulino/resolve-tor-dns-host

config: only normalize and resolve tor DNS host if it has changed

config.go

@@ -438,6 +438,9 @@ func loadConfig() (*config, error) {
 	}
 	cfg.Tor.SOCKS = socks.String()
 
+	// We'll only attempt to normalize and resolve the DNS host if it hasn't
+	// changed, as it doesn't need to be done for the default.
+	if cfg.Tor.DNS != defaultTorDNS {
 		dns, err := lncfg.ParseAddressString(
 			cfg.Tor.DNS, strconv.Itoa(defaultTorDNSPort),
 			cfg.net.ResolveTCPAddr,
@@ -446,6 +449,7 @@ func loadConfig() (*config, error) {
 			return nil, err
 		}
 		cfg.Tor.DNS = dns.String()
+	}
 
 	control, err := lncfg.ParseAddressString(
 		cfg.Tor.Control, strconv.Itoa(defaultTorControlPort),