upgrade: adtrust update_tdo_gidnumber plugin must check if adtrust is installed
    
    During upgrade, the plugin update_tdo_gidnumber is launched in order to
    add a gidnumber to the Trusted Domain Object.
    This plugin should not be run when ad trust is not installed, otherwise an
    error message is displayed.
    
    https://pagure.io/freeipa/issue/6881
    
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>