Unlinked from new spawn by removal of old spawn point

When you have linked to somebody else's spawn point, if you link to a different spawn point, the removal of the first spawn point can unlink you from the new spawn. This does not appear to work when it is your own mobile spawn point that is undone.

Steps to reproduce:
1. Link to _somebody else's_ mobile spawn point
2. Link to a new mobile spawn point
3. Have the person undo their spawn point
4. You will be unlinked from the new mobile spawn point