Fix typo in /support/security

Author: nmisch

templates/security/security.html

@@ -63,7 +63,7 @@ <h2>CVE Numbering Authority</h2>
 <p>
   <strong>NOTE:</strong> The security team will only assign CVEs to projects
   when requested by members of the project. If you think you've found a security
-  issue in a project other than PostgreSQL or it's packages and installers,
+  issue in a project other than PostgreSQL or its packages and installers,
   please contact the security team for that project. See below for more details.
 </p>