ldap_int_thread_pool_wrapper was called with wrong prototype (ITS#1673)

ldap_int_thread_pool_wrapper was called with wrong prototype  (ITS#1673)

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Written by Hallvard B. Furuseth and placed into the public domain.
This software is not subject to any license of the University of Oslo.
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ldap_int_thread_pool_wrapper() was defined with an parameter
struct ldap_int_thread_pool_s* but called with a void* argument.
Since these may have different representations, it can crash.

Hallvard B. Furuseth <h.b.furuseth@usit.uio.no>, March 2002.