Fix for CF7 add_uploaded_file

gistfile1.php

public function add_uploaded_file( $name, $file_path ) {
    $mail = $this->contact_form->prop('mail');
	$this->uploaded_files[$name] = $file_path;

	if ( empty( $this->posted_data[$name] ) ) {
		$this->posted_data[$name] = basename( $file_path );
		    
		$mail['attachments'] .= "[$name]\n";
		$this->form->set_properties( array('mail' => $mail) );
	}
}