Enable native windowing system settings with SDL platform

Source/Editor/Options/InterfaceOptions.cs

@@ -167,7 +167,7 @@ namespace FlaxEditor.Options
         [EditorDisplay("Interface"), EditorOrder(10), Tooltip("Editor User Interface scale. Applied to all UI elements, windows and text. Can be used to scale the interface up on a bigger display. Editor restart required.")]
         public float InterfaceScale { get; set; } = 1.0f;
 
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS || PLATFORM_SDL
         /// <summary>
         /// Gets or sets a value indicating whether use native window title bar. Editor restart required.
         /// </summary>