Teleporting to the emergency shuttle is broken

[RikuTheKiller]

Cause:

@Absolucy
The pull request #3349 causes teleporting to the emergency shuttle to fail while it's in transit.

Confirmation:

I might fully confirm this bug myself later, but I heard a report of it in-game with the error message given.
The only source of this error message is this PR, so something is fucked up here, that's for sure.

UPDATE: I've also heard a report of it on the Discord now.

Expected Behaviour:

Before the PR, teleport beacons worked on the shuttle both in transit and at CentCom.
This behaviour should be restored and kept as-is, including while the shuttle is at CentCom.

Reproduction:

1. Place a teleport beacon on the shuttle.
2. Attempt to teleport to the shuttle after it has left.
3. Get the error message "something holds you back!".
4. Get marooned on the station.