stop the duplicate remove of the root part ids from the full part and local part indexes in SG.DeleteSceneObject()

this is unnecessary because the parts array iterated through contains the root part as well as the non-root parts

OpenSim/Region/Framework/Scenes/Tests/SceneObjectBasicTests.cs

@@ -135,7 +135,7 @@ namespace OpenSim.Region.Framework.Scenes.Tests
 
             // Now delete the scene object and check again
             scene.DeleteSceneObject(so, false);
-            
+
             Assert.That(scene.GetGroupByPrim(so.LocalId), Is.Null);
             Assert.That(scene.GetGroupByPrim(parts[partsToTestCount - 1].LocalId), Is.Null);
         }