Use calculated config members.

urls.go

@@ -117,7 +117,7 @@ func (b *URLBuilder) Encode() string {
 	}
 
 	u := url.URL{
-		Host: b.mapper.Config.FullHost,
+		Host: b.mapper.Config.CalculatedHostname(),
 	}
 
 	if !b.External {
@@ -126,11 +126,7 @@ func (b *URLBuilder) Encode() string {
 	} else {
 		// Override scheme only if we're forcing external links.
 		if b.Scheme == "" {
-			if b.mapper.Config.Protocol != "" {
-				u.Scheme = b.mapper.Config.Protocol
-			} else {
-				u.Scheme = "http"
-			}
+			u.Scheme = b.mapper.Config.CalculatedProtocol()
 		} else {
 			u.Scheme = b.Scheme
 		}