Replace taglib with pre-existing one

[guusdk]

This repository introduces a new taglib, which is used to pull in property values in JSP pages.

the 'admin' tag lib that exists in Openfire should already provide this functionality. Lets use that instead.

<%@ taglib uri="admin" prefix="admin"%>
...
<input type="text" name="bundleId" size="80" value='${admin:getProperty("pushserver.apple.apns.bundleId", "")}' />