### Summary Trying to save the Datadog integration settings when a parent project has been configured for integration will fail to save with an error:  ### Steps to reproduce 1. Configure DataDog integration under Settings → Integrations → DataDog on a namespace with at least one existing project. 1. Set the existing project to `Use Custom Settings` with any values (valid or not) in the API URL and API Key fields 1. Save 1. Select `Use Default Settings` and save. ### Example Project https://gitlab.com/gitlab-silver/datadog-test/ ### What is the current *bug* behavior? Unable to revert integration to use Default settings ### What is the expected *correct* behavior? Able to apply Default settings ### Relevant logs and/or screenshots ### Output of checks This bug happens on Gitlab.com: ` GitLab Enterprise Edition 14.1.0-pre 4d9b43f1227 ` ### Possible fixes <!-- If you can, link to the line of code that might be responsible for the problem. -->