[HL2MP] Prevent deleting vital entities

[speedvoltage]

Issue: Deleting certain entities crashes the game. Obviously, deleting worldspawn is a bad idea for example.

Fix: Prevent deleting vital entities responsible for running the game properly.

[ficool2]

This is a poor way of going about it. You can bypass it by changing the classname of the entity, for example ent_fire player addoutput "classname abc";ent_remove abc (you can also workaround this with ent_create). You should not be doing any classname comparisons