Comment 2 for bug 1894056

Thought we get this on VPNaaS:

"+++ neutron-db-manage --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/plugins/ml2/ml2_conf.ini --subproject neutron-vpnaas upgrade head",
    "INFO [alembic.runtime.migration] Context impl MySQLImpl.",
    "INFO [alembic.runtime.migration] Will assume non-transactional DDL.",
    "/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/script/revision.py:152: UserWarning: Revision 24f28869838b referenced from 24f28869838b -> 41b509d10b5e (head), VPNaaS endpoint groups is not present",
    " util.warn(",
    "Traceback (most recent call last):",
    " File \"/var/lib/kolla/venv/bin/neutron-db-manage\", line 8, in <module>",
    " sys.exit(main())",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/neutron/db/migration/cli.py\", line 635, in main",
    " return_val |= bool(CONF.command.func(config, CONF.command.name))",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/neutron/db/migration/cli.py\", line 179, in do_upgrade",
    " run_sanity_checks(config, revision)",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/neutron/db/migration/cli.py\", line 619, in run_sanity_checks",
    " script_dir.run_env()",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/script/base.py\", line 489, in run_env",
    " util.load_python_file(self.dir, \"env.py\")",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/util/pyfiles.py\", line 98, in load_python_file",
    " module = load_module_py(module_id, path)",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/util/compat.py\", line 184, in load_module_py",
    " spec.loader.exec_module(module)",
    " File \"<frozen importlib._bootstrap_external>\", line 783, in exec_module",
    " File \"<frozen importlib._bootstrap>\", line 219, in _call_with_frames_removed",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/neutron_vpnaas/db/migration/alembic_migrations/env.py\", line 88, in <module>",
    " run_migrations_online()",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/neutron_vpnaas/db/migration/alembic_migrations/env.py\", line 79, in run_migrations_online",
    " context.run_migrations()",
    " File \"<string>\", line 8, in run_migrations",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/runtime/environment.py\", line 846, in run_migrations",
    " self.get_context().run_migrations(**kw)",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/runtime/migration.py\", line 509, in run_migrations",
    " for step in self._migrations_fn(heads, self):",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/neutron/db/migration/cli.py\", line 609, in check_sanity",
    " for script in script_dir.revision_map.iterate_revisions(",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/script/revision.py\", line 777, in _iterate_revisions",
    " uppers = util.dedupe_tuple(self.get_revisions(upper))",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/script/revision.py\", line 321, in get_revisions",
    " resolved_id, branch_label = self._resolve_revision_number(id_)",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/script/revision.py\", line 501, in _resolve_revision_number",
    " self._revision_map",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/util/langhelpers.py\", line 230, in __get__",
    " obj.__dict__[self.__name__] = result = self.fget(obj)",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/script/revision.py\", line 156, in _revision_map",
    " down_revision = map_[downrev]",
    "KeyError: '24f28869838b'"