Enabling openvpn_tls_auth leads to an error in the Read TLS-auth key task.
When openvpn_tls_auth is set, the openvpn_tls_key file is created in tasks/authentication/tls.yml. The same file is read in tasks/core/read-client-files.yml (when openvpn_tls_auth and openvpn_unified_client_profiles are set). In ff24a35 the order of creation and reading was swapped: now reading the openvpn_tls_key file is attempted before the file is created.