Polish

See gh-20704

spring-boot-project/spring-boot-docs/src/docs/asciidoc/spring-boot-features.adoc

@@ -1413,7 +1413,7 @@ These are:
 
 The default unit is bytes and can be overridden using `@DataSizeUnit` as illustrated in the sample above.
 
-TIP: If you are upgrading from a previous version that is simply using `Long` to express the size, make sure to define the unit (using `@DataSizeUnit`) if it isn't bytes alongside the switch to `DataSize`.
+TIP: If you are upgrading a `Long` property, make sure to define the unit (using `@DataSizeUnit`) if it isn't bytes.
 Doing so gives a transparent upgrade path while supporting a much richer format.