fix:线下课编辑默认图传参修改

src/modules/course-manage/offline-course/AddOfflineCourse.jsx

 /*
  * @Author: 吴文洁
  * @Date: 2020-08-05 10:07:47
- * @LastEditors: wufan
- * @LastEditTime: 2021-05-27 19:25:48
+ * @LastEditors: yuananting
+ * @LastEditTime: 2021-06-07 15:06:26
  * @Description: 线下课新增/编辑页
  * @Copyright: 杭州杰竞科技有限公司 版权所有
  */
@@ -518,6 +518,11 @@ class AddOfflineCourse extends React.Component {
     if(coverId){
       scheduleMediaRequests = [coverObj]
     }
+
+    // 编辑且使用默认图时不传
+    if (pageType === 'edit' && coverUrl === defaultCoverUrl) {
+      scheduleMediaRequests = []
+    }
     const commonParams = {
       categoryId,
       courseName,