Fix preview display after uploading a PDF twice with a deletion

Steps to reproduce:

1. Navigate to your personal workspace
2. Create a File document : only set the title
3. The File document is displayed
4. Click on the link "Upload main file" and select a PDF file
5. Observe that the page is refreshed and the preview is correctly displayed => all good
6. Delete the attachment with the "Delete" button => the page is refreshed with no preview
7. Click on the link "Upload main file" and select the same PDF file as at step 4
8. Observe that the page is refreshed, the file name is displayed (with the size and the controls to delete/preview/dowload) but no preview is displayed <= that's the bug

Expected behavior: the preview is displayed after deleting the main attachment and uploading it again

Note that

• I was not able to reproduce on LTS 2021/WebUI 3.0.19
• the preview is correctly displayed if one refreshes the page