Error when changing project locale

[willemarcel]

Create a project and don't add any additional information. Add a mapping type, change the locale to another language and save. The default locale of the project is updated, but the project_info for the new language is not created.

After that, the project will be inaccessible due to an error on the API:

[2021-02-05 15:45:04,815] CRITICAL in project_info: BAD DATA: no info for project 16, locale: en, default None
[2021-02-05 15:45:04,816] CRITICAL in resources: Project GET - unhandled error: BAD DATA: no info for project 16, locale: en, default None

Related to #4208