修复自定义组件`file-upload`无法显示第一个文件，列表显示的文件比实际文件少一个的问题

@@ -26,7 +26,7 @@
 
 
     <!-- 文件列表 -->
     <!-- 文件列表 -->
     <transition-group class="upload-file-list el-upload-list el-upload-list--text" name="el-fade-in-linear" tag="ul">
     <transition-group class="upload-file-list el-upload-list el-upload-list--text" name="el-fade-in-linear" tag="ul">
-      <li :key="file.uid" class="el-upload-list__item ele-upload-list__item-content" v-for="(file, index) in fileList">
+      <li :key="file.url" class="el-upload-list__item ele-upload-list__item-content" v-for="(file, index) in fileList">
         <el-link :href="`${baseUrl}${file.url}`" :underline="false" target="_blank">
         <el-link :href="`${baseUrl}${file.url}`" :underline="false" target="_blank">
           <span class="el-icon-document"> {{ getFileName(file.name) }} </span>
           <span class="el-icon-document"> {{ getFileName(file.name) }} </span>
         </el-link>
         </el-link>