Fix crash in script for quest Trolls is gone crazy

--HG--
branch : trunk

sql/updates/6405_world.sql

@@ -0,0 +1,4 @@
+DELETE FROM `spell_script_target` WHERE `entry`=55083;
+INSERT INTO `spell_script_target` (`entry`, `type`, `targetEntry`) VALUES
+(55083, 1, 29700),
+(55083, 1, 29686);

src/bindings/scripts/scripts/northrend/zuldrak.cpp

@@ -158,7 +158,7 @@ struct TRINITY_DLL_DECL npc_captured_rageclawAI : public ScriptedAI
             return;
 
         if (DespawnTimer <= uiDiff)
-            m_creature->setDeathState(JUST_DIED);
+            m_creature->DisappearAndDie();
         else DespawnTimer -= uiDiff;
    }
 };