Remove any-user DML capability from allow_system_table_mods
Previously, allow_system_table_mods allowed a non-superuser to do DML
on a system table without further permission checks. This has been
removed, as it was quite inconsistent with the rest of the meaning of
this setting. (Since allow_system_table_mods was previously only
accessible with a server restart, it is unlikely that anyone was using
this possibility.)
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/
8b00ea5e-28a7-88ba-e848-
21528b632354%402ndquadrant.com