Gajim CSS is not reloaded after switching dark/light theme

Please first check if another issue has been opened for your problem

Versions

• OS: Debian Bullseye
• Gajim version: 1.4.0-dev1+c6fd3959
• GTK version: 3.24.24
• Python-nbxmpp version: 2.0.1

Steps to reproduce the problem

1. Change system theme to dark
2. Start Gajim
3. Open a room where members sent links

Expected behavior

Links should have system link color that is light and have sufficient contrast.

Actual behavior

Links have a dark blue color and don't have sufficient contrast.