PostgreSQL importer does not work with new config parsing

[Gerrrr]

Following examples in docs https://github.com/apache/otava/blob/master/docs/POSTGRESQL.md

Before #86

$ docker-compose -f examples/postgresql/docker-compose.yaml run --build otava otava analyze aggregate_mem --update-postgres
...
INFO: Computing change points for test aggregate_mem...
time    experiment_id    commit    config_id    process_cumulative_rate_mean    process_cumulative_rate_stderr    process_cumulative_rate_diff
------  ---------------  --------  -----------  ------------------------------  --------------------------------  ------------------------------

After #86

$ docker-compose -f examples/postgresql/docker-compose.yaml run --build otava otava analyze aggregate_mem --update-postgres
usage: otava [-h] [--config-file CONFIG_FILE] [--graphite-url GRAPHITE_URL]
             [--grafana-url GRAFANA_URL] [--grafana-user GRAFANA_USER]
             [--grafana-password GRAFANA_PASSWORD] [--slack-token SLACK_TOKEN]
             [--postgres-hostname POSTGRES_HOSTNAME] [--postgres-port POSTGRES_PORT]
             [--postgres-username POSTGRES_USERNAME] [--postgres-password POSTGRES_PASSWORD]
             [--postgres-database POSTGRES_DATABASE] [--bigquery-project-id BIGQUERY_PROJECT_ID]
             [--bigquery-dataset BIGQUERY_DATASET] [--bigquery-credentials BIGQUERY_CREDENTIALS]
             {list-tests,list-metrics,list-groups,analyze,regressions,remove-annotations,validate}
             ...
otava: error: argument command: invalid choice: '--WHERE=e.exclude_from_analysis = false AND' (choose from 'list-tests', 'list-metrics', 'list-groups', 'analyze', 'regressions', 'remove-annotations', 'validate')