Log Message:
-----------
Fix the URL properly per Robert Treat.
Modified Files:
--------------
pgsql/doc/src/sgml:
external-projects.sgml (r1.17 -> r1.18)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/external-projects.sgml?r1=1.17&r2=1.18)