Bug Timeline Event side border when creating new event

Summary

There should be a solid border on the left hand side between events that occur on the same day, this should also be the case when adding a new event

Screenshot

Steps to reproduce

1. Navigate to Monitor > Incidents page
2. Create new or open an existing incident
3. Navigate to Timeline tab of the incident
4. Click "Add new timeline event" button at the bottom
5. Add some sample text
6. Click "Save and add another event"
7. Observe broken border on left hand side

Possible fixes

The logic for the CSS of the left hand border is all within app/assets/stylesheets/page_bundles/incidents.scss#L14-L66

Implementation Guide