Fix perms when linking an object. Set root part perms to the perms

of the link set to make the build floater behave consistently.
Fixes permissions exploit introduced on 23 August.

OpenSim/Region/Framework/Scenes/Scene.Inventory.cs

@@ -2503,6 +2503,12 @@ namespace OpenSim.Region.Framework.Scenes
             }
 
             m_sceneGraph.LinkObjects(root, children);
+
+            ScenePresence sp;
+            if (TryGetScenePresence(agentId, out sp))
+            {
+                root.SendPropertiesToClient(sp.ControllingClient);
+            }
         }
 
         private string PermissionString(uint permissions)