Bogus pg_class.relminmxid value for pg_database

Right after a fresh initdb on a 9.3 or master database:

postgres=# select oid,relname,relminmxid from pg_class where
relname='pg_database';
  oid  |   relname   | relminmxid
------+-------------+------------
  1262 | pg_database | 4244967297
(1 row)

That bogus value seems to appear already some time during initdb. The
relminmxid for all other tables is 1, which is correct.

- Heikki