Merge branch 'xiaoqin' into mergeBranch

src/SManagement/archives/components/FileList.vue

@@ -11,7 +11,7 @@
       <div class="image">
         <el-image
           style="width: 100%; height: 100%"
-          :src="item.cover"
+          :src="item.cover || require('../../../assets/file_icons/unknow.png')"
           fit="fill">
         </el-image>
       </div>