Available locales not properly updated

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@ThiloWitt copied translates into a 3.1 test site, went into the Settings module and saw all locales there. Afterwards this error occured: Invalid configuration at path "jms_i18n_routing.default_locale": The default locale must be one of the configured locales..

The problems was caused by config/packages/zikula_settings.yaml which was not properly updated. It contained:

zikula_settings:
    locales:
        1: es

Things worked after he changed it to:

zikula_settings:
    locales:
        1: en
        2: es