UI: Fix missing newline at the end of a file

UI/window-basic-preview.cpp

@@ -1237,4 +1237,4 @@ void OBSBasicPreview::SetScalingAmount(float newScalingAmountVal) {
 	scrollingOffset.x *= newScalingAmountVal / scalingAmount;
 	scrollingOffset.y *= newScalingAmountVal / scalingAmount;
 	scalingAmount = newScalingAmountVal;
-}
+}