When an oar is loaded, do not create a default parcel before loading the parcels from the OAR.

The region spanning parcel shouldn't exist in this situation.  If it does, when the land data is loaded it is repersisted with a local ID which comes after the ones loaded via the oar, which obliterates the oar loaded one.

Resaving the data we just loaded from the database is somewhat odd in itself (though this makes sense from the way that OAR loading was already using the same event).

OpenSim/Region/RegionCombinerModule/RegionCombinerLargeLandChannel.cs

@@ -63,9 +63,9 @@ public class RegionCombinerLargeLandChannel : ILandChannel
             return RootRegionLandChannel.AllParcels();
         }
         
-        public void Clear()
+        public void Clear(bool setupDefaultParcel)
         {
-            RootRegionLandChannel.Clear();
+            RootRegionLandChannel.Clear(setupDefaultParcel);
         }
 
         public ILandObject GetLandObject(int x, int y)