Scanner is strict single concurrent use

[noci2012]

Describe the bug A single temporary file is used for ALL scans. (/tmp/img)

To Reproduce Steps to reproduce the behavior: Let several people do a scan. (if multiple scanner are available).

Expected behavior No confusion...

Screenshots n/a

Desktop (please complete the following information):

• OS: Linux
• Browser n/a
• Version n/a

Smartphone (please complete the following information): n/a

Additional context Add any other context about the problem here.

[noci2012]

maybe this can be used for a temp name: https://www.php.net/manual/en/function.tempnam.php

[noci2012]

This is partly alleviated by #28 & #29