bug#74707: Bad URLs in "Badge code" section of package pages in the web package browser.

[Yuval Langer]

Example:

https://packages.guix.gnu.org/packages/emacs-greader

The address in the "Badge code" section is:

http://127.0.0.1:3000/packages/emacs-greader/

not for:

http://packages.guix.gnu.org/packages/emacs-greader/

same for the SVG file address.