Small typo on support/security

There seems to be a small singular/plural typo on the support/security page
regarding contrib module components unless my english is off: “a ..  modules”.
See attached patch.

cheers ./daniel

--- a/templates/pages/support/security.html
+++ b/templates/pages/support/security.html
@@ -427,7 +427,7 @@ The following component references are used in the above table:
  <tr valign="top">   <td class="colFirst">contrib module</td>
-   <td class="colLast">This vulnerability exists in a contrib modules. Contrib modules are not installed by default
whenPostgreSQL is installed from source. They may be installed by binary packages.</td> 
+   <td class="colLast">This vulnerability exists in a contrib module. Contrib modules are not installed by default
whenPostgreSQL is installed from source. They may be installed by binary packages.</td> 
  </tr>