Index: Fix definition for memberOf
    
    The index definition for memberOf is inconsistent:
    
    dn: cn=memberOf,cn=index,cn=userRoot,cn=ldbm database,cn=plugins,cn=config
    cn: member
    nsIndexType: eq
    nsIndexType: sub
    nsSystemIndex: false
    objectClass: top
    objectClass: nsIndex
    
    The cn attribute should be memberOf, not member. Fix the definition.
    
    Fixes: https://pagure.io/freeipa/issue/8920
    Signed-off-by: Florence Blanc-Renaud <flo@redhat.com>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>