Read/write racing issue with `config.json`

[majorz]

During an update there is delay due to network unavailability and/or the needed time for fetching the config from the API endpoint, which causes a racing issue with other services that write to config.json. When merging data back to config.json we need to use a fresh copy of it. This will hugely minimize the chance for such a racing issue to occur. We need do add an integration test for this as well.

[pritamghanghas]

what is the racing issue causing? A corrupt json?
We are also facing corrupt json issues but those look like filesystem corruption issues.