fix(course): 修改用户不存在时的错误码

- 将用户不存在的错误码从404改为401-保持错误信息内容不变
- 确保公开课逻辑不受影响

fs-service/src/main/java/com/fs/course/service/impl/FsUserCourseVideoServiceImpl.java

@@ -2046,7 +2046,7 @@ public class FsUserCourseVideoServiceImpl implements IFsUserCourseVideoService
         //查询用户
        FsUser fsUser = fsUserMapper.selectFsUserById(param.getUserId());
          if (fsUser == null){
-            return ResponseResult.fail(404,"当前用户信息不存在");
+             return ResponseResult.fail(401,"当前用户信息不存在");
         }
         //公开课
         if (param.getIsOpenCourse()!=null && param.getIsOpenCourse()==1){