Issue title: Canon PIXMA MG3600 Series
 Issue body: https://forums.linuxmint.com/viewtopic.php?f=51&t=325428

> device `pixma:04A9178A' is a CANON Canon PIXMA MG3600 Series multi-function peripheral
device `escl:http://116.69.203.115:60000' is a ESCL MG3600 series flatbed scanner
device `airscan:e0:MG3600 series' is a eSCL MG3600 series eSCL network scanner

Scanning did not originally work until sane-airscan was installed.
 Comments: 
 Comment 0: Looks like it works with `sane-escl` and was never tested with `sane-airscan`'. Why it didn't work initially is not very clean
 Comment 1: On Mon 20 Jul 2020 at 05:56:10 -0700, Alexander Pevzner wrote:

> Looks like it works with `sane-escl` and was never tested with
> `sane-airscan`'. Why it didn't work initially is not very clean

You win some; you lose some. :)

Thanks,

Brian.

 Comment 2: We should spread the rumor, that installing `sane-airscan` magically cures even unrelated problems :-)
 Comment 3: I said: 

> You win some; you lose some.

Looks like we won this one. The user now responds:

> eSCL MG3600 series ' this is the one that works for me many thanks again

Cheers,

Brian.
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