小小训练营群组改造，更改群编号数据类型

mec-student/src/main/java/com/ym/mec/student/controller/ActivityUserMapperController.java

@@ -1,11 +1,8 @@
 package com.ym.mec.student.controller;
 
-import com.ym.mec.auth.api.client.SysUserFeignService;
-import com.ym.mec.auth.api.entity.SysUser;
 import com.ym.mec.biz.service.ActivityUserMapperService;
 import com.ym.mec.common.controller.BaseController;
 import com.ym.mec.common.entity.HttpResponseResult;
-import com.ym.mec.common.exception.BizException;
 import io.swagger.annotations.Api;
 import io.swagger.annotations.ApiOperation;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -13,8 +10,6 @@ import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
-import java.util.Optional;
-
 @RequestMapping("activityUserMapper")
 @Api(tags = "活动排课服务")
 @RestController