Setting "Support translated aliases in URLs" is only visible when "Activate the edition of content in multiple languages" is enabled.
I don't need edition in multiple languages.
So, you need to enable "Activate the edition of content in multiple languages", click Save, enable "Support translated aliases in URLs" and disable "Activate the edition of content in multiple languages", click Save.
Thanks for idea, at least it works, though looks frustrating for the end user:
"Support translated aliases in URLs" setting should be always visible, even if "Activate the edition of content in multiple languages" is disabled.