Update ClassTransformer.java

Added code to stop HostileWorlds from spawning the boss pyramid.
Update ClassTransformer.java

Changed code to add a return instruction to the start of the method, rather than deleting instructions.
Merge pull request #1 from Blargerist/patch-1

Stop the HostileWorlds mod from spawning the boss pyramid
 * The boss can spawn inside of solid blocks when the pyramid is generated and suffocate