The `tmpfilename` is generated by pve-http-server and always adheres to this pattern, so make this explicit to prevent confusion and have a more complete JSON API schema, useful for e.g., the API viewer. Signed-off-by: Friedrich Weber <f.weber@proxmox.com> [ T: slightly extended commit message ] Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>