#6 segfault - NULL not 0 for rb_struct_define

[MKitt]

On amd64 machines a segfault occurs. This is traced to
rb_struct_define where the last argument is a 0. This
last argument should be NULL. On amd64 0 and NULL are
quite different.

line 475 of misc.c (0.9.5) needs to use a NULL instead
of a 0:

rb_sLDAP_APIInfo = rb_struct_define ("APIInfo",
"info_version", /* ldapai_xxxx */
"api_version",
"protocol_version",
"extensions",
"vendor_name",
"vendor_version", NULL);