ContentNotFoundException inapproporate with missing MinimumRoles setting

Description

Steps to reproduce

1. Customize settings to set RequiredRole setting to "ApiGroup" and do not set MinimumRoles setting in code -> Authorization header is not required in this case.

     var options = new ContentApiOptions
            {
                MultiSiteFilteringEnabled = false,
                RequiredRole = "ApiGroup"
            };

2. Create the user group "ApiGroup" having no rights for all content.
3. Send a GET request without an Authorization header for getting content data:

{{EPCMSHost}}/api/episerver/v1.0/content/5

Expected:
Returns error code 403 Forbidden with an informative error message.

Actual:
Returns error code 404 "Content was not found" even though the published content #5 exists on the site. The exception in log file as below is not related to the root cause that is a matching group and minimum access rights for MinimumRoles setting.

ERROR EPiServer.ContentApi.Controllers.ContentApiController: Content was not found
EPiServer.Core.ContentNotFoundException: Content was not found
   at EPiServer.ContentApi.Controllers.ContentApiController.ResultFromContent(IContent content, String expand)
   at EPiServer.ContentApi.Controllers.ContentApiController.Get(String contentReference, List`1 languages, String expand)