v12 relnotes: alter system tables

https://www.postgresql.org/docs/12/release-12.html

|Allow modifications of system catalogs' options using ALTER TABLE (Peter Eisentraut)
|Modifications of catalogs' reloptions and autovacuum settings are now supported.

I wonder if that should say: "... WHEN ALLOW_SYSTEM_TABLE_MODS IS ENABLED."

Justin