Use correct social and search engines list when internet is disabled #15951

Ignore any saved value in the options table for social and search engines list when internet is disabled. Technically, the list stored in the options table could still be newer when disabling internet but it would become outdated as soon as there's a Matomo update. Mentioned in the issue we could also alternatively delete the option entry on update but somehow thought it might be easier this way.

fix https://github.com/matomo-org/matomo/issues/15923