Revert "会员等级配置等级有效期不能为空"

This reverts commit 710a7b68.

yudao-module-member/yudao-module-member-impl/src/main/java/cn/iocoder/yudao/module/member/dal/dataobject/level/MemberUserLevelConfigDO.java

@@ -52,6 +52,7 @@ public class MemberUserLevelConfigDO extends BaseDO {
     /**
      * 等级有效期(数字正整数或为空)
      */
+    @TableField(updateStrategy = FieldStrategy.IGNORED)
     private Integer validityPeriod;
     /**
      * 积分累计周期(数字正整数或为空)