Fix saving of file association settings (Windows)

src/preferences/options_imp.cpp

@@ -143,6 +143,10 @@ options_imp::options_imp(QWidget *parent):
   connect(comboTrayIcon, SIGNAL(currentIndexChanged(int)), this, SLOT(enableApplyButton()));
 #if defined(Q_WS_X11) && !defined(QT_DBUS_LIB)
   checkPreventFromSuspend->setDisabled(true);
+#endif
+#ifdef Q_WS_WIN
+  connect(checkAssociateTorrents, SIGNAL(toggled(bool)), this, SLOT(enableApplyButton()));
+  connect(checkAssociateMagnetLinks, SIGNAL(toggled(bool)), this, SLOT(enableApplyButton()));
 #endif
   // Downloads tab
   connect(textSavePath, SIGNAL(textChanged(QString)), this, SLOT(enableApplyButton()));