The DB update of my phpBB 3.0.12 installation to 3.2.11 fails (can not use newer phpBB because my Debian server has only php 5.6.x).

 I am using PostgresQL 13 and the error message is:

ERROR: column "consrc" does not exist

SQLSELECT consrc as constraint_data FROM pg_constraint, pg_class bc WHERE

The column "consrc" was removed from the Postgres system table "pg_constraint" with Postgres version 12, release October 2019.

The Postgres documentation also says, consrc should not be used, use pg_get_constraintdef(oid) instead. Any idea how to fix this?