Trac Ticket #346 - Slow ldapmodify operation time for large
    quantities of multi-valued attribute values
    
    https://fedorahosted.org/389/ticket/346
    
    Fix Description: When comparing dn syntax attribute values (e.g.,
    member in a group) with filter values, filter values are case-
    lowered, but the attribute values in an entry are not any more.
    This patch lowers the case before the comparison in the syntax
    plugin.
    (cherry picked from commit 091166e8c0642380d96cb495e30471b0bb4a5c94)