Fix resending file transfer with 'null' file. On cancellation, the...

Julien Wadel
2024-03-04T16:34:58Z

Fix resending file transfer with 'null' file. On cancellation, the filetransfer is not reset that lead the message to have its Content as not isFile().
Then, next call to send() was done with no isFile() in its contents.
- Restore the content.