Issue 50919 - Backend delete fails using dsconf
    
    Description:  Fix typo in parser argument name
    
    relates: https://pagure.io/389-ds-base/issue/50919
    
    Reviewed by: mreynolds(one line commit rule)
    
    (cherry picked from commit 5fb047137d4079e81baf795d9fdc26f572ec5bf1)