Delete Javadoc references to removed code

See gh-18755

Author: Cosmin Humeniuc

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/servlet/MultipartConfigFactory.java

@@ -21,9 +21,7 @@
 import org.springframework.util.unit.DataSize;
 
 /**
- * Factory that can be used to create a {@link MultipartConfigElement}. Size values can be
- * set using traditional {@literal long} values which are set in bytes or using more
- * convenient {@link DataSize} variants.
+ * Factory that can be used to create a {@link MultipartConfigElement}.
  *
  * @author Phillip Webb
  * @since 1.4.0