Don't try to save a NPCs attachment states on NPC delete

OpenSim/Region/CoreModules/Avatar/Attachments/AttachmentsModule.cs

@@ -468,6 +468,14 @@ namespace OpenSim.Region.CoreModules.Avatar.Attachments
         /// <param name="grp"></param>
         private void UpdateKnownItem(IScenePresence sp, SceneObjectGroup grp)
         {
+            // Saving attachments for NPCs messes them up for the real owner!
+            INPCModule module = m_scene.RequestModuleInterface<INPCModule>();
+            if (module != null)
+            {
+                if (module.IsNPC(sp.UUID, m_scene))
+                    return;
+            }
+
             if (grp.HasGroupChanged || grp.ContainsScripts())
             {
                 m_log.DebugFormat(