In the migration to *SqlEngine in 0.34.4 to 0.34.5, the server config's respect
for the default value for autocommit regressed. In 0.34.5 - 0.35.3,
`autocommit` is always turned on by default for incoming connections,
regardless of the setting in the config.yaml file or the flag
`--no-auto-commit` being passed at the command line.