Prevent Lihzahrd Altar from being moved at all in Survival

[GlasiaVD23 (Glasia)]

@UncleFubar

Fighting bosses anywhere on the spawn island is just a bad idea.

It is not only a bad dea, it is forbidden (S10#7):

@system

#7 Bosses

The spawn area is not to be used for boss fights. Any bosses being fought at spawn can and most likely will be despawned without loot drops.