spec file: bump minimal required version of 389-ds-base
    
    Require 389-ds-base >= 1.3.5.14 for:
    https://fedorahosted.org/389/ticket/48992
    
    https://fedorahosted.org/freeipa/ticket/6369
    
    Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>