Skanlite fails with "sane_start= Invalid argument"

[Marco Sulla]

I have a Canon TS6350 connected to the WLAN to the Lubuntu 20.04.2. I installed the official updated Canon drivers.

Skanlite is able to connect to the printer with or without encryption (port 80 or 443). When I press the button, Scan, the scan is done by the printer. At the end of the scan, Skanlite reports me "sane_start= Invalid argument":

```
$ skanlite
"deviceOption value="
Icon theme "elementary" not found.
("image/bmp", "image/jpeg", "image/png", "image/tiff", "image/vnd.microsoft.icon", "image/vnd.wap.wbmp", "image/webp", "image/x-icns", "image/x-portable-bitmap", "image/x-portable-graymap", "image/x-portable-pixmap", "image/x-xbitmap", "image/x-xpixmap")
"escl:https://xxx.xxx.xxx.xxx:443"
"escl:http://xxx.xxx.xxx.xxx:80"
"escl:https://xxx.xxx.xxx.xxx:443"
"escl:http://xxx.xxx.xxx.xxx:80"
Capability : [image/jpeg]
Capability : [image/jpeg]
"escl:https://xxx.xxx.xxx.xxx:443"
"escl:https://xxx.xxx.xxx.xxx:443"
"escl:http://xxx.xxx.xxx.xxx:80"
sane_start= Invalid argument
```

$ uname -a
Linux mikehal 5.4.0-77-generic #86-Ubuntu SMP Thu Jun 17 02:35:03 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

Skanlite version 2.1.0.1