add convex state to mesh key, so a change is detected.

OpenSim/Framework/PrimitiveBaseShape.cs

@@ -880,6 +880,11 @@ namespace OpenSim.Framework
         }
 
         public ulong GetMeshKey(Vector3 size, float lod)
+        {
+            return GetMeshKey(size, lod, false);
+        }
+
+        public ulong GetMeshKey(Vector3 size, float lod, bool convex)
         {
             ulong hash = 5381;
 
@@ -926,6 +931,9 @@ namespace OpenSim.Framework
                     hash = djb2(hash, scaleBytes[i]);
             }
 
+            if(convex)
+                hash = djb2(hash, 0xa5);
+
             return hash;
         }