Re-open the ldif file to prevent error message
    
    There was an issue with ipa-server-upgrade and it was
    showing an error while upgrading:
    DN... does not exists or haven't been updated, caused
    by not moving pointer to file begining when re-reading.
    
    Resolves: https://pagure.io/freeipa/issue/7644
    Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>
    Reviewed-By: Christian Heimes <cheimes@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>