[Satellite 6] Error 'Manifest foreman_proxy_plugin_openscap/manifests/init.pp was not found' while upgrading Red Hat Capsule server

Issue

Upgrading the Red Hat Capsule server failed with error:

Manifest foreman_proxy_plugin_openscap/manifests/init.pp was not found in /usr/share/katello-installer-base/modules, /usr/share/foreman-installer/modules
/usr/share/gems/gems/kafo-0.7.6.1/lib/kafo/puppet_module.rb:29:in `join': no implicit conversion of nil into String (TypeError)
        from /usr/share/gems/gems/kafo-0.7.6.1/lib/kafo/puppet_module.rb:29:in `initialize'
        from /usr/share/gems/gems/kafo-0.7.6.1/lib/kafo/configuration.rb:88:in `new'
        from /usr/share/gems/gems/kafo-0.7.6.1/lib/kafo/configuration.rb:88:in `block in modules'
        from /usr/share/gems/gems/kafo-0.7.6.1/lib/kafo/configuration.rb:88:in `map'
        from /usr/share/gems/gems/kafo-0.7.6.1/lib/kafo/configuration.rb:88:in `modules'
        from /usr/share/gems/gems/kafo-0.7.6.1/lib/kafo/configuration.rb:184:in `params'
        from /usr/share/gems/gems/kafo-0.7.6.1/lib/kafo/configuration.rb:193:in `preset_defaults_from_puppet'
        from /usr/share/gems/gems/kafo-0.7.6.1/lib/kafo/kafo_configure.rb:251:in `set_parameters'
        from /usr/share/gems/gems/kafo-0.7.6.1/lib/kafo/kafo_configure.rb:97:in `initialize'
        from /usr/share/gems/gems/clamp-0.6.2/lib/clamp/command.rb:125:in `new'
        from /usr/share/gems/gems/clamp-0.6.2/lib/clamp/command.rb:125:in `run'
        from /usr/share/gems/gems/kafo-0.7.6.1/lib/kafo/kafo_configure.rb:148:in `run'
        from /sbin/satellite-installer:12:in `<main>''