Update dnf-plugins-extras to rev 2 via SR 752753
    
    https://build.opensuse.org/request/show/752753
    by user dimstar_suse
    - Upgrade to version 4.0.8
      + [system-upgrade] Save gpgcheck and repo_gpgcheck repo options (rh#1693677)
      + Add showvars plugin for showing what DNF vars are set for the dnf runtime
      + [system-upgrade] Use --system-upgrade plymouth mode (rh#1681584)
      + [system-upgrade] Fix traceback caused by setting gpgcheck options (rh#1751103, rh#1746346)
      + Fix kickstart plugin (rh#1649093)
      + [system-upgrade] Ensure identical transaction in download and update steps (rh#1758588)
      + [system-upgrade] Provide distro specific url for help with system-upgrade
      + Set clean_requirements_on_remove=False during remove (rh#1764169)
    - Set rpmconf plugin package to replace yum-merge-conf on Tumbleweed
    - Backport patch from upstream to rename man pages to dnf-FOO (rh#1706386)
      * Patch: 0001-doc-move-manpag