用户中心（百搭）YtUser修复自带界面购买页面错误；优化会员等级显示名称；

3 个文件发生了变化
第一个： YtUser/template/t_buy.php 
                {if !$zbp->Config('YtUser')->payment}
                <li class="col-24 col-m-24"><p class="tx-input-full"><button type="button" onclick="return Ytbuypay();" class="tx-btn tx-btn-big bg-black">提交</button></p></li>
                {else}
                {if $zbp->Config('YtUser')->payment=='2'}
                <li class="col-24 col-m-24"><p class="tx-input-full"><button type="button" onclick="return Ytbuypay();" class="tx-btn tx-btn-big bg-black">余额支付</button></p></li>
                {/if}
                <li class="col-24 col-m-24"><p class="tx-input-full"><button type="button" onclick="return VipRegPage();" class="tx-btn tx-btn-big bg-black">支付宝</button></p></li>
                <script type="text/javascript">function VipRegPage(){document.getElementById("edit").action="{$host}zb_users/plugin/YtUser/cmd.php?act=UploadPst&token={$zbp->GetToken()}";}</script>
                {/if}
第二个： YtUser/template/t_upgrade.php 
{template:t_header}
<div class="col-19 col-m-24">
    <div class="tx-box bg-white pd15 mb15">
        <h2 class="f-22 mb10">会员级别：{if $user.Level > 4}普通会员{else}VIP会员{/if} {if $user.Level < 5}<span class="f-14">到期时间：{if $user.Level == 1}永久有效{else}{$user.Vipendtime}{/if}</span>{/if}</h2>
        <h2 class="f-22 mb10">会员级别：{if $user.Level > 4}普通用户{else}VIP会员{/if} {if $user.Level < 5}<span class="f-14">到期时间：{if $user.Level == 1}永久有效{else}{$user.Vipendtime}{/if}</span>{/if}</h2>
        <p>{$zbp.Config('YtUser').readme_text}</p>
    </div>
第三个： YtUser/template/t_user.php 
<div class="col-19 col-m-24">
    <div class="user-information">
        <ul class="row">
            <li class="col-6 col-m-12 mb15"><a href="{$host}{$zbp->Config('YtUser')->YtUser_Upgrade}" class="bg-cyan"><i class="iconfont icon-crown"></i>   {if $user.Level < 4}VIP会员{else}普通会员{/if}</a></li>
            <li class="col-6 col-m-12 mb15"><a href="{$host}{$zbp->Config('YtUser')->YtUser_Upgrade}" class="bg-cyan"><i class="iconfont icon-crown"></i>   {if $user.Level <= 4}VIP会员{else}普通用户{/if}</a></li>
            <li class="col-6 col-m-12 mb15"><a href="{$host}{$zbp->Config('YtUser')->YtUser_Integral}" class="bg-blue"><i class="iconfont icon-recharge"></i> 余额 {$user.YtUser('Price')} </a></li>
            <li class="col-6 col-m-12 mb15"><a href="{$host}{$zbp->Config('YtUser')->YtUser_Articlelist}" class="bg-orange"><i class="iconfont icon-copy"></i> 文章 {$zbp->user->Articles}</a></li>
            <li class="col-6 col-m-12 mb15"><a href="{$host}{$zbp->Config('YtUser')->YtUser_Commentlist}" class="bg-green"><i class="iconfont icon-liuyan"></i> 评论 {$zbp->user->Comments}</a></li>