Add Peter Geoghegan to Security team page

Author: Joe Conway <mail@joeconway.com>
Discussion: https://postgr.es/m/a89d3579-0131-496f-b595-219dfca8b4fe@joeconway.com

Author: danielgustafsson

templates/security/security.html

@@ -342,6 +342,7 @@ <h2>The PostgreSQL Security Team</h2>
   <li>Nathan Bossart</li>
   <li>Noah Misch</li>
   <li>Peter Eisentraut</li>
+  <li>Peter Geoghegan</li>
   <li>Robert Haas</li>
   <li>Stefan Kaltenbrunner</li>
   <li>Tom Lane</li>