Ticket #47559 hung server - related to sasl and initialize
    
    https://fedorahosted.org/389/ticket/47559
    Reviewed by: ???
    Branch: master
    Fix Description: Use a mutex to protect calls to openldap functions that do
    anything with crypto - bind, unbind, start_tls, other calls.
    Platforms tested: RHEL6 x86_64
    Flag Day: no
    Doc impact: no