Fixes error 500 when trying to open Samba app page when at least
one of the users in freedombox-share group doesn't exist.
Tests performed in both stable and testing containers:
- Installed Samba app.
- Installed Deluge app (Plinth install/setup fails but the Debian
package itself was installed).
- Did `apt remove --purge deluged` from command line.
- Checked that the debian-deluged user doesn't exist (`getent passwd`)
and the user is in the freedombox-share group (`getent group`).
- Checked that the Samba app page opens without errors.
- Checked that all the Samba tests pass.
Fixes#2411.
Signed-off-by: Veiko Aasa <veiko17@disroot.org>
Reviewed-by: Sunil Mohan Adapa <sunil@medhas.org>
22671510e6