更改站点配置加载出错的提示

lib/pages/welcome_page.dart

@@ -39,7 +39,8 @@ class WelcomePageController extends GetxController {
         ),
       );
     } catch (err, stack) {
-      alert(Get.overlayContext!, ErrorUtils.getErrorMessage(err), title: "错误");
+      // ignore: prefer_interpolation_to_compose_strings
+      alert(Get.overlayContext!, "无法加载站点配置：" + ErrorUtils.getErrorMessage(err), title: "错误");
       if (kDebugMode) {
         print("Exception in logout: $err");
         stack.printError();