[url_image_preview] Support for XHTML-IM
Whenever I get a new image URL, I see the image completely unscaled at 100% zoom in the chat window.
But when closing the chat and reopening it, suddenly, the images are properly scaled.
This is with Gajim 1.1.1, url_image_preview 2.3.23 and Ubuntu 18.10 but it's also happening with Gajim under Windows 7 and Windows 10.