docs - remove upgrade topic from pxf subnav for 6.0
<li><a href="/6-0/pxf/cfghostport.html" format="markdown">Configuring the PXF Agent Host and Port (Optional)</a> </li>
</ul>
</li>
- <li><a href="/6-0/pxf/upgrade_pxf.html" format="markdown">Upgrading PXF</a></li>
<li><a href="/6-0/pxf/cfginitstart_pxf.html" format="markdown">Starting, Stopping, and Restarting PXF</a></li>
<li><a href="/6-0/pxf/using_pxf.html" format="markdown">Granting Users Access to PXF</a></li>
<li><a href="/6-0/pxf/reg_jar_depend.html" format="markdown">Registering PXF JAR Dependencies</a></li>
