[Users] Save attachment replacing spaces with X - alternate character requested

[flyingrhino]

Hi,

When saving attachments, claws replaces spaces in the filename with 'X' .
Is there a config item somewhere that I can use '_' instead of 'X' ?
I can't seem to find it in clawsrc.

I'm using claws 3.11.1 which is the latest on LM 17.3 repos.

Thanks.