Documentation pages not clickable when the phases are over

[Didayolo]

@bbearce I think you have worked on a similar problem already but I am not able to find it.

When all phases are over, these links become unclickable:

[Didayolo]

Sorry @bbearce I assign you to this too, to avoid forgetting about this issue.

Basically, I think that when there is no current phase, some variable is missing and makes the pages bug.

This older fix was related to that: #1344

[ihsaan-ullah]

+1 Same problem in a competition where all phases have ended.

[pemo-ml]

I've also experienced this issue when testing my competition where none of the phases have started yet.
It would only load the first page and the markdown page defined in terms.

The links worked again when I set the start date ahead to currently be in the first phase.