Merge pull request #9687 from jasonsturges/mirrortexture-update

Mirror Texture expression statement is not assignment or call

src/Materials/Textures/mirrorTexture.ts

@@ -153,7 +153,7 @@ export class MirrorTexture extends RenderTargetTexture {
 
         this._updateGammaSpace();
         this._imageProcessingConfigChangeObserver = scene.imageProcessingConfiguration.onUpdateParameters.add(() => {
-            this._updateGammaSpace;
+            this._updateGammaSpace();
         });
 
         const engine = this.getScene()!.getEngine();