Upgrading to Qt 5.13.2 broke fontconfig

[Lucianmusat]

I recently upgraded to 5.13.2 from 5.13.1 and now the fonts are all weird and the app spits an error log at start:

Fontconfig error: Cannot load default config file

The issue gets fixed if I run "export FONTCONFIG_PATH=/etc/fonts" before running the program, but I want a more permanent solution.
I build with Conan and qt:with_freetype=True and the system is Ubuntu 16.04/Mint 19.2