Remove unused SceneManager.TryGetAvatarsScene()

It makes far more sense anyway to use TryGetRootScenePresence().Scene, in common with the rest of the code
This method could also return any scene for child or root agents, depending in which order the scenes happened to lie in the list

OpenSim/Region/Framework/Scenes/SceneManager.cs

@@ -562,26 +562,6 @@ namespace OpenSim.Region.Framework.Scenes
             return false;
         }
 
-        public bool TryGetAvatarsScene(UUID avatarId, out Scene scene)
-        {
-            ScenePresence avatar = null;
-
-            lock (m_localScenes)
-            {
-                foreach (Scene mScene in m_localScenes)
-                {
-                    if (mScene.TryGetScenePresence(avatarId, out avatar))
-                    {
-                        scene = mScene;
-                        return true;
-                    }
-                }
-            }
-
-            scene = null;
-            return false;
-        }
-
         public void CloseScene(Scene scene)
         {
             lock (m_localScenes)