docs - pxf max tomcat threads now user-configurable (#7887)

* docs - pxf max tomcat threads now user-configurable

* misc edits

gpdb-doc/markdown/pxf/troubleshooting_pxf.html.md.erb

@@ -271,8 +271,6 @@ PXF thread capacity is determined by the profile and whether or not the data is
 
 Perform the following procedure to set the maximum number of Tomcat threads for the PXF agent running on each segment host in your Greenplum Database deployment.
 
-You will need to re-apply these configuration changes after any PXF version upgrades.
-
 1. Log in to your Greenplum Database master node:
 
     ``` shell