[Publication] Fix deletion of file when editing project

[CamilleBeau]

Brief summary of changes

In this PR the deleteUpload function of ProjectFormFields class in projectFields.js is fixed by changing the syntax of the swal.

• Have you updated related documentation?

Testing instructions (if applicable)

1. Propose a project with a file
2. Edit that project and attempt to delete the file.
3. When you click the X next to the file, a swal should show up.
4. If you click "No, cancel it" in the swal, make sure that the file is kept.
5. If you click "Yes, I am sure" in the swal, make sure that the file is removed.

Link(s) to related issue(s)

• Resolves [publication] Front-end error on file deletion #9135

[sruthymathew123]

All the testing instructions are followed and works as expected!

[sruthymathew123]

@driusan This is good to go.