fix for builds with no start date throwing an error in cycle analytics events Instead of the error, we should inform that there is no start date - [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added - Tests - [x] Added for this feature/bug - [x] All builds are passing - [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html) - [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides) - [x] Branch has no merge conflicts with `master` (if it does - rebase it please) - [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits) ## What are the relevant issue numbers? Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/24925 See merge request !7738