【im消息】下载地址替换，数据修复方法

health-im/health-im-biz/src/main/java/com/renkang/im/service/impl/ImServiceImpl.java

@@ -1,5 +1,6 @@
 package com.renkang.im.service.impl;
 
+import cn.hutool.core.util.ObjectUtil;
 import cn.hutool.core.util.StrUtil;
 import com.alibaba.fastjson.JSON;
 import com.alibaba.fastjson.JSONArray;
@@ -526,7 +527,7 @@ public class ImServiceImpl implements ImService {
                             default:
                         }
                     }
-                    if (isRepair) {
+                    if (isRepair && ObjectUtil.isNotNull(jsonObject)) {
                         imMsgRecordAllMapper.update(new LambdaUpdateWrapper<ImMsgRecordAll>()
                                 .eq(ImMsgRecordAll::getId, imMsgRecordAll.getId())
                                 .set(ImMsgRecordAll::getMsgcontent, jsonObject.toJSONString())