Fixed a crash when opening a project's Timeline view

Opening a project's Timeline view could take the whole page down with "An unhandled error has occurred" — but only when none of the project's dated task lists fell inside the initial one-month window around today. A project whose list dates sat entirely in the past or further out in the future hit it every time, while a project with something scheduled near today never did, which made the crash look random.

The Timeline now opens cleanly in that case and shows the "Nothing in this window" nudge as intended, so you can pan or widen the zoom to reach your lists.