Attachment is lost if attach button is clicked after attaching

[andrechalella]

Describe the bug
After attaching a file, if I click the attachment button again and subsequently cancel the "open file" dialog, the file is effectively removed, although the button keeps showing the file name as if all was okay.

To Reproduce
Steps to reproduce the behavior:

1. Click "Select or drop file attachment"
2. Choose a file and press OK
3. Click the attachment button again (this time the button caption will be "Attached: ")
4. This time, click CANCEL on the dialog
5. Notice that the file name persists on the button
6. Try to "Save"
7. Notice it does not save

Expected behavior
I would expect either:

• file remains valid
• file name is cleared from the button

Desktop (please complete the following information):

• OS: Server: Debian Docker / Client: Windows
• Browser: Chrome
• Version: 148.0.7778.181

Additional context
If text is filled in addition to the file, the pasta saves, but without the file (only text).