Flatpak & KeePassXC - Fix browser integration

To fix browser integration, you have to create just a symlink to keepassxc-proxy:

sudo ln -s /var/lib/flatpak/app/org.keepassxc.KeePassXC/current/active/files/bin/keepassxc-proxy /usr/bin/keepassxc-proxy

Source: https://discussion.fedoraproject.org/t/article-proposal-keepassxc-with-flatpak-browser-integration-and-clipboard/24342