Fix NFS unit names
    
    NFS unit names were renamed.
    Compatibility was maintained with older unit names
    through symlinks. When these symlinks are removed
    only new unit names work, so changing to using non-
    symlink unit names is required.
    
    Fixes: https://pagure.io/freeipa/issue/7783
    Signed-off-by: François Cami <fcami@redhat.com>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>