Stakeholder Engagement attachment function is broken.

[ianliuwk1019]

Describe the Bug
A FOM user reported the attachment is not working and always get the message "The file type is not accepted".

Expected Behaviour
Should allow valid file type attachment to be uploaded.

Acceptance Criteria

• Fix and verify the attachment can be uploaded with valid file types.
• Keep original error message when attached file file type is not valid.

Additional context
Add any other context about the problem here.

[ianliuwk1019]

Fixed and deployed to PROD