Do not replace Obsidian and Bedrock in prepare arenas

Signed-off-by: Lixfel <agga-games@gmx.de>

FightSystem_Core/src/de/steamwar/fightsystem/fight/FightSchematic.java

@@ -145,7 +145,7 @@ public class FightSchematic extends StateDependent {
 
     @Override
     public void disable() {
-        if(!Config.ReplaceObsidianBedrock)
+        if(!Config.ReplaceObsidianBedrock || Config.mode == ArenaMode.PREPARE)
             return;
 
         FreezeWorld freezer = null;