@ Koval
Perhaps I wasn't clear:
I run Linux. There is no 4.9 to download, unless the script is downloading 4.9 and it's just the page text that's wrong?
Page
https://calibre-ebook.com/download_linux
Text
Download for Linux
The latest release of calibre is 4.8.0. What's new.
What's New:
https://calibre-ebook.com/whats-new
Release: 4.8 [03 Jan, 2020]
Certainly there is a 4.9 listed for Windows, though it has the 4.8 What's New.
Perhaps you didn't upload it, or it's a cached page from somewhere I'm seeing?
P.S. Thanks again for all the good work on this.