Fix a crash in void reaver script

--HG--
branch : trunk

src/bindings/scripts/scripts/outland/tempest_keep/the_eye/boss_void_reaver.cpp

@@ -123,6 +123,9 @@ struct TRINITY_DLL_DECL boss_void_reaverAI : public ScriptedAI
             for(std::list<HostilReference *>::iterator itr = t_list.begin(); itr!= t_list.end(); ++itr)
             {
                 target = Unit::GetUnit(*m_creature, (*itr)->getUnitGuid());
+                if (!target)
+                    continue;
+
                 // exclude pets & totems
                 if (target->GetTypeId() != TYPEID_PLAYER)
                     continue;