s3-libads: Use the configured LDAP page size.

s3-libads: Use the configured LDAP page size.

We already allow the user to configure LDAP page size, and use it in pdb_ldap.
But then we hard-code the initial LDAP page size value to 1000 in ads_init, so
it doesn't take effect there.  So let's use the configured LDAP page size value
in ads_init also, which defaults to 1000.

Signed-off-by: Justin Maggard <jmaggard@netgear.com>
Reviewed-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
Autobuild-User(master): Volker Lendecke <vl@samba.org>
Autobuild-Date(master): Fri Jan 15 03:59:16 CET 2016 on sn-devel-144