Downgrade/lock mautrix-facebook to pre-mobile times

The `mobile` branch got merged to `master`, which ends up becoming
`:latest`. It's a "rewrite" of the bridge's backend and only
supports a Postgres database.

We'd like to go back (well, forward) to `:latest`, but that will take
a little longer, because:
- we need to handle and document things for people still on SQLite
(especially those with external Postgres, who are likely on SQLite for
bridges)
- I'd rather test the new builds (and migration) a bit before
releasing it to others and possibly breaking their bridge

Brave ones who are already using the bridge with Postgres
can jump on `:latest` and report their experience.

roles/matrix-bridge-mautrix-facebook/defaults/main.yml

@@ -7,7 +7,7 @@ matrix_mautrix_facebook_container_image_self_build: false
 matrix_mautrix_facebook_container_image_self_build_repo: "https://github.com/tulir/mautrix-facebook.git"
 
 # See: https://mau.dev/tulir/mautrix-facebook/container_registry
-matrix_mautrix_facebook_docker_image: "{{ matrix_mautrix_facebook_docker_image_name_prefix }}tulir/mautrix-facebook:latest"
+matrix_mautrix_facebook_docker_image: "{{ matrix_mautrix_facebook_docker_image_name_prefix }}tulir/mautrix-facebook:da1b4ec596e334325a1589e70829dea46e73064b"
 matrix_mautrix_facebook_docker_image_name_prefix: "{{ 'localhost/' if matrix_mautrix_facebook_container_image_self_build else 'dock.mau.dev/' }}"
 matrix_mautrix_facebook_docker_image_force_pull: "{{ matrix_mautrix_facebook_docker_image.endswith(':latest') }}"