The docs you referenced have a comment attached that suggests to disable SELINUX.
At least it’s worth a try (but I’d prefer to have SELINUX enabled).
If it is really SELINUX, https://wiki.centos.org/HowTos/SELinux section 5 might have some hints.
On Debian/Ubuntu I’d look whether the referenced file is installed or missing.
Can you provide the output of “ls -lZ /etc/privacyidea/privacyideaapp.wsgi” ?