fix: remove graph when selecting unreachable server

Assets/ETSI.ARF/ARF World Storage API/Editor/Windows/WorldGraphWindow.cs

@@ -47,9 +47,13 @@ namespace Assets.ETSI.ARF.ARF_World_Storage_API.Editor.Windows
         public static void ShowWindowFromWorldStorageWindow(WorldStorageServer server, WorldStorageUser user)
         {
             var window = GetWindow<WorldGraphWindow>("Graph Editor", true, typeof(SceneView));
-            if (window.myGraph != null && window.myGraph.ServerAndLocalDifferent() && EditorUtility.DisplayDialog("Saving node positions", "The World Graph has been modified. \nWould you like to push the modifications to the server ?", "Yes", "No"))
+            if (window.myGraph != null)
             {
-                window.myGraph.SaveInServer();
+                if (window.myGraph.ServerAndLocalDifferent() && EditorUtility.DisplayDialog("Saving node positions", "The World Graph has been modified. \nWould you like to push the modifications to the server ?", "Yes", "No"))
+                {
+                    window.myGraph.SaveInServer();
+                }
+                window.rootVisualElement.Remove(window.myGraph);
             }
             GraphEditorWindow.ResetWindow();
             window.worldStorageServer = server;