指定element-ui依赖版本为2.15.8，规避2.15.9版本中Prop being mutated: "placement"报错的bug

修复部分svg图标引用草料二维码插件内部字体的问题
去除短信日志页面的新增按钮，解决"handleAdd" is not defined的报错
修复数据库文档页面中data定义src: "undefined"的格式，解决控制台报错

yudao-ui-admin/src/views/system/sms/smsLog.vue

@@ -44,10 +44,6 @@
 
     <!-- 操作工具栏 -->
     <el-row :gutter="10" class="mb8">
-      <el-col :span="1.5">
-        <el-button type="primary" plain icon="el-icon-plus" size="mini" @click="handleAdd"
-                   v-hasPermi="['system:sms-log:create']">新增</el-button>
-      </el-col>
       <el-col :span="1.5">
         <el-button type="warning" plain icon="el-icon-download" size="mini" @click="handleExport" :loading="exportLoading"
                    v-hasPermi="['system:sms-log:export']">导出</el-button>