Core/Creatures: Added check for creature_equip_template.id = 0. 0 is a special value telling core to unequip all items

sql/updates/world/2014_03_20_00_world_creature_equip_template.sql

@@ -0,0 +1 @@
+UPDATE `creature_equip_template` SET `id`=1 WHERE `id`=0;

src/server/game/Globals/ObjectMgr.cpp

@@ -1087,6 +1087,11 @@ void ObjectMgr::LoadEquipmentTemplates()
         }
 
         uint8 id = fields[1].GetUInt8();
+        if (!id)
+        {
+            TC_LOG_ERROR("sql.sql", "Creature equipment template with id 0 found for creature %u, skipped.", entry);
+            continue;
+        }
 
         EquipmentInfo& equipmentInfo = _equipmentInfoStore[entry][id];