dblink-ldap - dblink-ldap: Add PG_MODULE_MAGIC, as required per 8.2.

Log Message:
-----------
Add PG_MODULE_MAGIC, as required per 8.2. *blush* for not doing this
earlier.

Modified Files:
--------------
dblink-ldap:
dblink-ldap.c (r1.3 -> r1.4)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/dblink-ldap/dblink-ldap/dblink-ldap.c.diff?r1=1.3&r2=1.4)