Fixed an irritating problem with nss_ldap and pam_ldap. Since these

Fixed an irritating problem with nss_ldap and pam_ldap.  Since these
modules are dynamically loaded, they summon libldap when needed.
However, depending on the security libraries available when the
shared libldap was built, the latter brings up other dependencies.
On some platforms, it seems that no solution is available: no
indirect dynamic dependencies.  But for some platforms where this
is supported (in particular, Linux), the shared libldap must
contain info on what other dynamic libraries it needs.  We were
failing to put this info into the shared library.  This patch
seems to fix it.