fix(rootfs): enable archive_mode before initial boot

It appears that the first WAL log is (occasionally) not being shipped to minio, and that's because
we did not enable `archive_mode = on` for the first database boot in `003_restore_from_backup.sh`,
which starts shipping WAL logs immediately after booting. We enable archive mode in 004. This is a
simple fix that just requires us enabling archive_mode in `003_restore_from_backup.sh` before we
boot up the server.

rootfs/docker-entrypoint-initdb.d/003_restore_from_backup.sh

@@ -2,6 +2,9 @@
 
 cat << EOF >> "$PGDATA/postgresql.conf"
 wal_level = archive
+archive_mode = on
+archive_command = 'envdir "${WALE_ENVDIR}" wal-e wal-push %p'
+archive_timeout = 60
 EOF
 
 # ensure $PGDATA has the right permissions
@@ -28,6 +31,9 @@ lc_numeric = 'C'      # locale for number formatting
 lc_time = 'C'       # locale for time formatting
 default_text_search_config = 'pg_catalog.english'
 wal_level = archive
+archive_mode = on
+archive_command = 'envdir "${WALE_ENVDIR}" wal-e wal-push %p'
+archive_timeout = 60
 listen_addresses = '*'
 EOF
   cat << EOF > "$PGDATA/pg_hba.conf"