test_selfhosting_new_empty_then_users fails

Several build tests fail in Debian and Ubuntu. Here's an issue that may be responsible for multiple test failures.

Build logs

Click in the Status column at https://buildd.debian.org/status/package.php?p=glom

Build log excerpt

FAIL: tests/test_selfhosting_new_empty_then_users
=================================================

The files belonging to this database system will be owned by user "buildd".
This user must also own the server process.

The database cluster will be initialized with locale "C".
The default database encoding has accordingly been set to "SQL_ASCII".
The default text search configuration will be set to "english".

Data page checksums are disabled.

fixing permissions on existing directory /tmp/testglomUJXKRZ/glom_postgres_data/data ... ok
creating subdirectories ... ok
selecting default max_connections ... 100
selecting default shared_buffers ... 128MB
selecting dynamic shared memory implementation ... posix
creating configuration files ... ok
running bootstrap script ... ok
performing post-bootstrap initialization ... ok
syncing data to disk ... ok

WARNING: enabling "trust" authentication for local connections
You can change this by editing pg_hba.conf or using the option -A, or
--auth-local and --auth-host, the next time you run initdb.

Success. You can now start the database server using:

    /usr/lib/postgresql/11/bin/pg_ctl -D /tmp/testglomUJXKRZ/glom_postgres_data/data -l logfile start

Glom::DbUtils::type_vec_fields Glom::DbUtils::get_fields_for_table_from_database(const Glib::ustring&, bool):
 table_name=glom_system_preferences: data_model_fields->get_n_rows() == 0: The table probably
 does not exist in the specified database, or the user does not have SELECT rights.
Glom::DbUtils::type_vec_fields Glom::DbUtils::get_fields_for_table_from_database(const Glib::ustring&, bool):
 table_name=glom_system_preferences: data_model_fields->get_n_rows() == 0: The table probably
 does not exist in the specified database, or the user does not have SELECT rights.
bool test(Glom::Document::HostingMode): Privs::get_table_privileges() returned an unexpected
 view privilege for group=somegroup1, table_name=sometable
bool test_hosting_mode(const SlotTest&, Glom::Document::HostingMode, Glib::ustring): Failed with PostgreSQL
waiting for server to shut down.... done
server stopped
FAIL tests/test_selfhosting_new_empty_then_users (exit status: 1)

Other Info

See https://bugzilla.gnome.org/776288 for the 2-digit date problem.