fix: free resources in slots

GPClient/gpclient.h

@@ -9,6 +9,7 @@
 #include "portalconfigresponse.h"
 #include "settingsdialog.h"
 #include "vpn.h"
+#include "gatewayauthenticator.h"
 
 QT_BEGIN_NAMESPACE
 namespace Ui { class GPClient; }
@@ -80,6 +81,8 @@ private:
     SettingsDialog *settingsDialog;
     QPushButton *settingsButton;
 
+    GatewayAuthenticator *gatewayAuthenticator;
+
     bool isQuickConnect { false };
     bool isSwitchingGateway { false };
     PortalConfigResponse portalConfig;