【系统文档】新增可上传的mp4格式缺少格式icon

src/views/dictionary/attachment/components/SignatureTemplate/attachmentPreview.vue

@@ -70,6 +70,7 @@ import ppt from '@/assets/file_icon/ppt.png'
 import pptx from '@/assets/file_icon/pptx.png'
 import xls from '@/assets/file_icon/xls.png'
 import xlsx from '@/assets/file_icon/xlsx.png'
+import mp4 from '@/assets/file_icon/xlsx.png'
 import PreviewFile from '@/components/PreviewFile'
 import imageViewer from './image-viewer'
 import { getSystemDocumentAttachmentList } from '@/api/dictionary'
@@ -112,6 +113,7 @@ export default {
             pptx,
             xls,
             xlsx,
+            mp4,
             rowData: {},
             list: [],
             searchData: defaultSearchData(),