feat：优化loading工具

lib/utils/loading_utils.dart

@@ -4,6 +4,7 @@ export 'package:flutter_easyloading/flutter_easyloading.dart';
 
 class LoadingUtils {
   static void showLoading({String? text}) {
+    if(EasyLoading.isShow) return;
     EasyLoading.show(status: text, maskType: EasyLoadingMaskType.black);
   }