Ticket #348 - crash in ldap_initialize with multiple threads
    
    https://fedorahosted.org/389/ticket/348
    Resolves: Ticket #348
    Bug Description: crash in ldap_initialize with multiple threads
    Reviewed by: mreynolds (Thanks!)
    Branch: master
    Fix Description: Protect calls to ldap_initialize() with a mutex to prevent
    multiple threads from calling it at the same time.
    Platforms tested: RHEL6 x86_64
    Flag Day: no
    Doc impact: no
    (cherry picked from commit 23c088919f66de014ee7f9aad407468e51451405)