message: Update links color
diff: #include <QPainter>
  static const QString STYLE_FORMAT = ":/styles/%1";
  +static const QColor LINK_COLOR = "#2d9ad0";
  class QtumStyle : public QProxyStyle
  {
  @@ -86,6 +87,10 @@ void StyleSheet::setStyleSheet(QApplication *app, const QString& style_name)
  qtumStyle->setBaseStyle(mainStyle);
  app->setStyle(qtumStyle);
  + QPalette mainPalette(app->palette());
  + mainPalette.setColor(QPalette::Link, LINK_COLOR);
  + app->setPalette(mainPalette);
  +
  setObjectStyleSheet<QApplication>(app, style_name);
  }
  