fix interface scale step

Author: Alberto Iannaccone

arduino-ide-extension/src/browser/dialogs/settings/settings-component.tsx

@@ -31,7 +31,7 @@ const maxScale = InterfaceScale.ZoomLevel.toPercentage(
 const minScale = InterfaceScale.ZoomLevel.toPercentage(
   InterfaceScale.ZoomLevel.MIN
 );
-const scaleStep = InterfaceScale.ZoomLevel.Step.fromPercentage(
+const scaleStep = InterfaceScale.ZoomLevel.Step.toPercentage(
   InterfaceScale.ZoomLevel.STEP
 );