WebP images don't load without `webp-pixbuf-loader` installed
Description:
WebP images don't load in Gajim without webp-pixbuf-loader installed.
Additional info:
This is true as of the latest 2.0.4-1. The gdk-pixbuf2 dependency isn't sufficient (https://gitlab.gnome.org/GNOME/gdk-pixbuf/-/issues/103), and I think it makes sense to add a dependency on webp-pixbuf-loader so more media works out of the box.
Steps to reproduce:
- Receive a WebP image.
- There's a stack trace for the image not being supported (I don't have it at hand.)