url and port only editable if not direct or automatic

proxyface/gui/proxy.hxx

@@ -97,6 +97,11 @@ class Proxy: public QDialog, public Ui::Proxy {
                  .arg(QNetworkProxy::applicationProxy().port()));
     }
 
+    void on__type_currentIndexChanged(int index) {
+      _url->setEnabled(index!=0);
+      _port->setEnabled(index!=0);
+    }
+
     void on__save_clicked(bool=false) {
       QSettings s("SwissSign", "ProxySettings");
       s.setValue("default-type", _type->currentIndex());