Notifications API - adding a non-existing endpoint to notifications/defaults result in 500 internal server error

When trying to add a non-existing endpoint to notifications/defaults the response is 500 internal server error.

For example:

https://qa.cloud.redhat.com/api/notifications/v1.0/notifications/defaults/75101111-e2b3-4780-9d71-c31a58b393f1

Expected: return 404 not found error