CKEditor image alignment outdated

Hello,
I'd like to report the following issue:
From my colleague:
"
I've noticed that when I put an image in a rich text field and I want to align it, Hippo adds the align="" attribute to my <img>. That's invalid html, (deprecated since HTML 4.01 according to MDN). I'd like to have configurable classes to add to the <img> element, so that I can align the image with CSS.
"

Steps to reproduce:
1. open a rich text editor
2. insert an image
3. in the image dialogue select alignment (any will do)

Expected output: a class to style alignment on
Actual output: align="" attribute

At the moment we work around this using custom stylesets as described in http://www.onehippo.org/library/concepts/document-types/html-fields/customize-ckeditor-styles.html to add a class to the img tag.